diff --git a/SurveyBackend/SurveyBackend.API/Controllers/AuthController.cs b/SurveyBackend/SurveyBackend.API/Controllers/AuthController.cs
index 93fb89a..882c94b 100644
--- a/SurveyBackend/SurveyBackend.API/Controllers/AuthController.cs
+++ b/SurveyBackend/SurveyBackend.API/Controllers/AuthController.cs
@@ -1,5 +1,7 @@
 using Microsoft.AspNetCore.Mvc;
+using SurveyBackend.Core.Services;
 using SurveyBackend.DTOs;
+using SurveyBackend.Mappers.UserDTOs;
 
 namespace SurveyBackend.Controllers;
 
@@ -7,9 +9,24 @@ namespace SurveyBackend.Controllers;
 [Route("auth")]
 public class AuthController : ControllerBase
 {
-    [HttpPost("login")]
-    public async Task<IActionResult> GetToken([FromBody] UserLoginDto loginData)
+    private readonly IAuthorizationService _authorizationService;
+
+    public AuthController(IAuthorizationService authorizationService)
     {
-        return Ok();
+        _authorizationService = authorizationService;
+    }
+
+    [HttpPost("login")]
+    public async Task<IActionResult> LogIn([FromBody] UserLoginDto loginData)
+    {
+        var token = await _authorizationService.LogInUser(loginData.Email, loginData.Password);
+        return Ok(new { token = token });
+    }
+
+    [HttpPost("register")]
+    public async Task<IActionResult> Register([FromBody] UserRegistrationDto registerData)
+    {
+        var token = await _authorizationService.RegisterUser(UserRegistrationMapper.UserRegistrationToModel(registerData));
+        return Ok(new { token = token });
     }
 }
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.API/Mappers/UserDTOs/UserRegistrationMapper.cs b/SurveyBackend/SurveyBackend.API/Mappers/UserDTOs/UserRegistrationMapper.cs
new file mode 100644
index 0000000..5d98322
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.API/Mappers/UserDTOs/UserRegistrationMapper.cs
@@ -0,0 +1,16 @@
+using SurveyBackend.Core.Models;
+using SurveyBackend.Core.Services;
+using SurveyBackend.DTOs;
+
+namespace SurveyBackend.Mappers.UserDTOs;
+
+public static class UserRegistrationMapper
+{
+    public static User UserRegistrationToModel(UserRegistrationDto dto) => new User
+    {
+        Email = dto.Email,
+        FirstName = dto.FirstName,
+        LastName = dto.LastName,
+        Password = dto.Password,
+    };
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.API/Middlewares/ExceptionsMiddleware.cs b/SurveyBackend/SurveyBackend.API/Middlewares/ExceptionsMiddleware.cs
new file mode 100644
index 0000000..65c94f8
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.API/Middlewares/ExceptionsMiddleware.cs
@@ -0,0 +1,49 @@
+using SurveyBackend.Services.Exceptions;
+
+namespace SurveyBackend.Middlewares;
+
+public class ExceptionsMiddleware
+{
+    private readonly RequestDelegate _next;
+    private readonly ILogger<ExceptionsMiddleware> _logger;
+
+    public ExceptionsMiddleware(RequestDelegate next, ILogger<ExceptionsMiddleware> logger)
+    {
+        _next = next;
+        _logger = logger;
+    }
+
+    public async Task InvokeAsync(HttpContext context)
+    {
+        try
+        {
+            await _next(context);
+        }
+        catch (ServiceException ex)
+        {
+            context.Response.StatusCode = ex.StatusCode;
+            context.Response.ContentType = "application/json";
+
+            var response = new
+            {
+                error = ex.Message
+            };
+
+            await context.Response.WriteAsJsonAsync(response);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex.Message);
+
+            context.Response.StatusCode = 500;
+            context.Response.ContentType = "application/json";
+
+            var response = new
+            {
+                error = "Internal Server Error. GG WP, request bub fix"
+            };
+
+            await context.Response.WriteAsJsonAsync(response);
+        }
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.API/Program.cs b/SurveyBackend/SurveyBackend.API/Program.cs
index 2aa90b2..6a2bf3f 100644
--- a/SurveyBackend/SurveyBackend.API/Program.cs
+++ b/SurveyBackend/SurveyBackend.API/Program.cs
@@ -2,8 +2,14 @@ using System.Text;
 using Microsoft.AspNetCore.Authentication.JwtBearer;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.IdentityModel.Tokens;
+using SurveyBackend.Core.Repositories;
+using SurveyBackend.Core.Services;
 using SurveyBackend.Infrastructure;
 using SurveyBackend.Infrastructure.Data;
+using SurveyBackend.Infrastructure.Repositories;
+using SurveyBackend.Middlewares;
+using SurveyBackend.Services;
+using SurveyBackend.Services.Services;
 using SurveyLib.Core.Repositories;
 using SurveyLib.Core.Services;
 using SurveyLib.Infrastructure.EFCore.Data;
@@ -27,6 +33,13 @@ public class Program
 
         builder.Services.AddScoped<SurveyDbContext>(provider => provider.GetRequiredService<ApplicationDbContext>());
 
+        builder.Services.AddScoped<IUserRepository, UserRepository>();
+        builder.Services.AddScoped<IUserService, UserService>();
+
+        builder.Services.AddScoped<IPasswordHasher, Sha256PasswordHasher>();
+
+        builder.Services.AddScoped<IAuthorizationService, AuthorizationService>();
+
         builder.Services.AddScoped<ISurveyRepository, SurveyRepository>();
         builder.Services.AddScoped<ISurveyService, SurveyService>();
 
@@ -59,6 +72,8 @@ public class Program
             app.UseSwaggerUI();
         }
 
+        app.UseMiddleware<ExceptionsMiddleware>();
+
         app.UseAuthentication();
         app.UseAuthorization();
 
diff --git a/SurveyBackend/SurveyBackend.API/SurveyBackend.API.csproj b/SurveyBackend/SurveyBackend.API/SurveyBackend.API.csproj
index 3764109..b736412 100644
--- a/SurveyBackend/SurveyBackend.API/SurveyBackend.API.csproj
+++ b/SurveyBackend/SurveyBackend.API/SurveyBackend.API.csproj
@@ -10,13 +10,18 @@
     <ItemGroup>
         <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="8.0.14" />
         <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.2"/>
-        <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="9.0.3" />
+        <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.15">
+          <PrivateAssets>all</PrivateAssets>
+          <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+        </PackageReference>
+        <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="8.0.15" />
         <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0"/>
     </ItemGroup>
 
     <ItemGroup>
       <ProjectReference Include="..\SurveyBackend.Core\SurveyBackend.Core.csproj" />
       <ProjectReference Include="..\SurveyBackend.Infrastructure\SurveyBackend.Infrastructure.csproj" />
+      <ProjectReference Include="..\SurveyBackend.Services\SurveyBackend.Services.csproj" />
     </ItemGroup>
 
 </Project>
diff --git a/SurveyBackend/SurveyBackend.Core/Models/User.cs b/SurveyBackend/SurveyBackend.Core/Models/User.cs
index 78f2286..257d4fa 100644
--- a/SurveyBackend/SurveyBackend.Core/Models/User.cs
+++ b/SurveyBackend/SurveyBackend.Core/Models/User.cs
@@ -4,7 +4,7 @@ namespace SurveyBackend.Core.Models;
 
 public class User
 {
-    public string Id { get; set; }
+    public int Id { get; set; }
     public string Email { get; set; }
     public string FirstName { get; set; }
     public string LastName { get; set; }
diff --git a/SurveyBackend/SurveyBackend.Core/Repositories/IUserRepository.cs b/SurveyBackend/SurveyBackend.Core/Repositories/IUserRepository.cs
index 791059a..311742b 100644
--- a/SurveyBackend/SurveyBackend.Core/Repositories/IUserRepository.cs
+++ b/SurveyBackend/SurveyBackend.Core/Repositories/IUserRepository.cs
@@ -4,4 +4,5 @@ namespace SurveyBackend.Core.Repositories;
 
 public interface IUserRepository : IGenericRepository<User>
 {
+    public Task<User?> GetUserByEmail(string email);
 }
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Core/Services/IAuthorizationService.cs b/SurveyBackend/SurveyBackend.Core/Services/IAuthorizationService.cs
new file mode 100644
index 0000000..0237a22
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Core/Services/IAuthorizationService.cs
@@ -0,0 +1,9 @@
+using SurveyBackend.Core.Models;
+
+namespace SurveyBackend.Core.Services;
+
+public interface IAuthorizationService
+{
+    public Task<string> LogInUser(string email, string password);
+    public Task<string> RegisterUser(User user);
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Services/IPasswordHasher.cs b/SurveyBackend/SurveyBackend.Core/Services/IPasswordHasher.cs
similarity index 74%
rename from SurveyBackend/SurveyBackend.Infrastructure/Services/IPasswordHasher.cs
rename to SurveyBackend/SurveyBackend.Core/Services/IPasswordHasher.cs
index 52d1427..6e2ec29 100644
--- a/SurveyBackend/SurveyBackend.Infrastructure/Services/IPasswordHasher.cs
+++ b/SurveyBackend/SurveyBackend.Core/Services/IPasswordHasher.cs
@@ -1,4 +1,4 @@
-namespace SurveyBackend.Infrastructure.Services;
+namespace SurveyBackend.Core.Services;
 
 public interface IPasswordHasher
 {
diff --git a/SurveyBackend/SurveyBackend.Core/Services/IUserService.cs b/SurveyBackend/SurveyBackend.Core/Services/IUserService.cs
index 7d97a29..cd34c76 100644
--- a/SurveyBackend/SurveyBackend.Core/Services/IUserService.cs
+++ b/SurveyBackend/SurveyBackend.Core/Services/IUserService.cs
@@ -1,6 +1,10 @@
+using SurveyBackend.Core.Models;
+
 namespace SurveyBackend.Core.Services;
 
 public interface IUserService
 {
-    
+    public Task<User> GetUserByEmail(string email);
+    public Task<bool> IsEmailTaken(string email);
+    public Task CreateUserAsync(User user);
 }
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Core/SurveyBackend.Core.csproj b/SurveyBackend/SurveyBackend.Core/SurveyBackend.Core.csproj
index adbb79f..8cc2397 100644
--- a/SurveyBackend/SurveyBackend.Core/SurveyBackend.Core.csproj
+++ b/SurveyBackend/SurveyBackend.Core/SurveyBackend.Core.csproj
@@ -7,7 +7,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="8.0.14" />
+      <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="8.0.15" />
     </ItemGroup>
 
 </Project>
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/20250418123442_Initial.Designer.cs b/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/20250418123442_Initial.Designer.cs
new file mode 100644
index 0000000..b8b673d
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/20250418123442_Initial.Designer.cs
@@ -0,0 +1,321 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using SurveyBackend.Infrastructure.Data;
+
+#nullable disable
+
+namespace SurveyBackend.Infrastructure.Data.Migrations
+{
+    [DbContext(typeof(ApplicationDbContext))]
+    [Migration("20250418123442_Initial")]
+    partial class Initial
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "8.0.15");
+
+            modelBuilder.Entity("GroupUser", b =>
+                {
+                    b.Property<int>("GroupsId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("UsersId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("GroupsId", "UsersId");
+
+                    b.HasIndex("UsersId");
+
+                    b.ToTable("GroupUser");
+                });
+
+            modelBuilder.Entity("SurveyBackend.Core.Models.Group", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Label")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Groups");
+                });
+
+            modelBuilder.Entity("SurveyBackend.Core.Models.User", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("FirstName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("LastName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Password")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Answer", b =>
+                {
+                    b.Property<int>("CompletionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("QuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AnswerText")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("CompletionId", "QuestionId");
+
+                    b.HasIndex("QuestionId");
+
+                    b.ToTable("Answers");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.AnswerVariant", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("MultipleAnswerQuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("QuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("SingleAnswerQuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Text")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MultipleAnswerQuestionId");
+
+                    b.HasIndex("QuestionId");
+
+                    b.HasIndex("SingleAnswerQuestionId");
+
+                    b.ToTable("AnswerVariant");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Completion", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("FinishedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("SurveyId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SurveyId");
+
+                    b.ToTable("Completions");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionBase", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Discriminator")
+                        .IsRequired()
+                        .HasMaxLength(34)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("SurveyId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SurveyId");
+
+                    b.ToTable("Questions");
+
+                    b.HasDiscriminator().HasValue("QuestionBase");
+
+                    b.UseTphMappingStrategy();
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Survey", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Surveys");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.MultipleAnswerQuestion", b =>
+                {
+                    b.HasBaseType("SurveyLib.Core.Models.QuestionBase");
+
+                    b.HasDiscriminator().HasValue("MultipleAnswerQuestion");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.SingleAnswerQuestion", b =>
+                {
+                    b.HasBaseType("SurveyLib.Core.Models.QuestionBase");
+
+                    b.HasDiscriminator().HasValue("SingleAnswerQuestion");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.TextQuestion", b =>
+                {
+                    b.HasBaseType("SurveyLib.Core.Models.QuestionBase");
+
+                    b.HasDiscriminator().HasValue("TextQuestion");
+                });
+
+            modelBuilder.Entity("GroupUser", b =>
+                {
+                    b.HasOne("SurveyBackend.Core.Models.Group", null)
+                        .WithMany()
+                        .HasForeignKey("GroupsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("SurveyBackend.Core.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("UsersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Answer", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.Completion", "Completion")
+                        .WithMany("Answers")
+                        .HasForeignKey("CompletionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("SurveyLib.Core.Models.QuestionBase", "Question")
+                        .WithMany("Answers")
+                        .HasForeignKey("QuestionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Completion");
+
+                    b.Navigation("Question");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.AnswerVariant", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.QuestionVariants.MultipleAnswerQuestion", null)
+                        .WithMany("AnswerVariants")
+                        .HasForeignKey("MultipleAnswerQuestionId");
+
+                    b.HasOne("SurveyLib.Core.Models.QuestionBase", "Question")
+                        .WithMany()
+                        .HasForeignKey("QuestionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("SurveyLib.Core.Models.QuestionVariants.SingleAnswerQuestion", null)
+                        .WithMany("AnswerVariants")
+                        .HasForeignKey("SingleAnswerQuestionId");
+
+                    b.Navigation("Question");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Completion", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.Survey", "Survey")
+                        .WithMany("Completions")
+                        .HasForeignKey("SurveyId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Survey");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionBase", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.Survey", "Survey")
+                        .WithMany("Questions")
+                        .HasForeignKey("SurveyId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Survey");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Completion", b =>
+                {
+                    b.Navigation("Answers");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionBase", b =>
+                {
+                    b.Navigation("Answers");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Survey", b =>
+                {
+                    b.Navigation("Completions");
+
+                    b.Navigation("Questions");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.MultipleAnswerQuestion", b =>
+                {
+                    b.Navigation("AnswerVariants");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.SingleAnswerQuestion", b =>
+                {
+                    b.Navigation("AnswerVariants");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/20250418123442_Initial.cs b/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/20250418123442_Initial.cs
new file mode 100644
index 0000000..26fbf8b
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/20250418123442_Initial.cs
@@ -0,0 +1,243 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace SurveyBackend.Infrastructure.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class Initial : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "Groups",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    Label = table.Column<string>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Groups", x => x.Id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Surveys",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    Title = table.Column<string>(type: "TEXT", nullable: false),
+                    Description = table.Column<string>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Surveys", x => x.Id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Users",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    Email = table.Column<string>(type: "TEXT", nullable: false),
+                    FirstName = table.Column<string>(type: "TEXT", nullable: false),
+                    LastName = table.Column<string>(type: "TEXT", nullable: false),
+                    Password = table.Column<string>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Users", x => x.Id);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Completions",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    SurveyId = table.Column<int>(type: "INTEGER", nullable: false),
+                    FinishedAt = table.Column<DateTime>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Completions", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Completions_Surveys_SurveyId",
+                        column: x => x.SurveyId,
+                        principalTable: "Surveys",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Questions",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    SurveyId = table.Column<int>(type: "INTEGER", nullable: false),
+                    Title = table.Column<string>(type: "TEXT", nullable: false),
+                    Discriminator = table.Column<string>(type: "TEXT", maxLength: 34, nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Questions", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Questions_Surveys_SurveyId",
+                        column: x => x.SurveyId,
+                        principalTable: "Surveys",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "GroupUser",
+                columns: table => new
+                {
+                    GroupsId = table.Column<int>(type: "INTEGER", nullable: false),
+                    UsersId = table.Column<int>(type: "INTEGER", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_GroupUser", x => new { x.GroupsId, x.UsersId });
+                    table.ForeignKey(
+                        name: "FK_GroupUser_Groups_GroupsId",
+                        column: x => x.GroupsId,
+                        principalTable: "Groups",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_GroupUser_Users_UsersId",
+                        column: x => x.UsersId,
+                        principalTable: "Users",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "Answers",
+                columns: table => new
+                {
+                    CompletionId = table.Column<int>(type: "INTEGER", nullable: false),
+                    QuestionId = table.Column<int>(type: "INTEGER", nullable: false),
+                    AnswerText = table.Column<string>(type: "TEXT", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Answers", x => new { x.CompletionId, x.QuestionId });
+                    table.ForeignKey(
+                        name: "FK_Answers_Completions_CompletionId",
+                        column: x => x.CompletionId,
+                        principalTable: "Completions",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_Answers_Questions_QuestionId",
+                        column: x => x.QuestionId,
+                        principalTable: "Questions",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                });
+
+            migrationBuilder.CreateTable(
+                name: "AnswerVariant",
+                columns: table => new
+                {
+                    Id = table.Column<int>(type: "INTEGER", nullable: false)
+                        .Annotation("Sqlite:Autoincrement", true),
+                    QuestionId = table.Column<int>(type: "INTEGER", nullable: false),
+                    Text = table.Column<string>(type: "TEXT", nullable: false),
+                    MultipleAnswerQuestionId = table.Column<int>(type: "INTEGER", nullable: true),
+                    SingleAnswerQuestionId = table.Column<int>(type: "INTEGER", nullable: true)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_AnswerVariant", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_AnswerVariant_Questions_MultipleAnswerQuestionId",
+                        column: x => x.MultipleAnswerQuestionId,
+                        principalTable: "Questions",
+                        principalColumn: "Id");
+                    table.ForeignKey(
+                        name: "FK_AnswerVariant_Questions_QuestionId",
+                        column: x => x.QuestionId,
+                        principalTable: "Questions",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                    table.ForeignKey(
+                        name: "FK_AnswerVariant_Questions_SingleAnswerQuestionId",
+                        column: x => x.SingleAnswerQuestionId,
+                        principalTable: "Questions",
+                        principalColumn: "Id");
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Answers_QuestionId",
+                table: "Answers",
+                column: "QuestionId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_AnswerVariant_MultipleAnswerQuestionId",
+                table: "AnswerVariant",
+                column: "MultipleAnswerQuestionId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_AnswerVariant_QuestionId",
+                table: "AnswerVariant",
+                column: "QuestionId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_AnswerVariant_SingleAnswerQuestionId",
+                table: "AnswerVariant",
+                column: "SingleAnswerQuestionId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Completions_SurveyId",
+                table: "Completions",
+                column: "SurveyId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_GroupUser_UsersId",
+                table: "GroupUser",
+                column: "UsersId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Questions_SurveyId",
+                table: "Questions",
+                column: "SurveyId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "Answers");
+
+            migrationBuilder.DropTable(
+                name: "AnswerVariant");
+
+            migrationBuilder.DropTable(
+                name: "GroupUser");
+
+            migrationBuilder.DropTable(
+                name: "Completions");
+
+            migrationBuilder.DropTable(
+                name: "Questions");
+
+            migrationBuilder.DropTable(
+                name: "Groups");
+
+            migrationBuilder.DropTable(
+                name: "Users");
+
+            migrationBuilder.DropTable(
+                name: "Surveys");
+        }
+    }
+}
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/ApplicationDbContextModelSnapshot.cs b/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/ApplicationDbContextModelSnapshot.cs
new file mode 100644
index 0000000..db4d61e
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Infrastructure/Data/Migrations/ApplicationDbContextModelSnapshot.cs
@@ -0,0 +1,318 @@
+// <auto-generated />
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using SurveyBackend.Infrastructure.Data;
+
+#nullable disable
+
+namespace SurveyBackend.Infrastructure.Data.Migrations
+{
+    [DbContext(typeof(ApplicationDbContext))]
+    partial class ApplicationDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder.HasAnnotation("ProductVersion", "8.0.15");
+
+            modelBuilder.Entity("GroupUser", b =>
+                {
+                    b.Property<int>("GroupsId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("UsersId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("GroupsId", "UsersId");
+
+                    b.HasIndex("UsersId");
+
+                    b.ToTable("GroupUser");
+                });
+
+            modelBuilder.Entity("SurveyBackend.Core.Models.Group", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Label")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Groups");
+                });
+
+            modelBuilder.Entity("SurveyBackend.Core.Models.User", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("FirstName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("LastName")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Password")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Answer", b =>
+                {
+                    b.Property<int>("CompletionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("QuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("AnswerText")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("CompletionId", "QuestionId");
+
+                    b.HasIndex("QuestionId");
+
+                    b.ToTable("Answers");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.AnswerVariant", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("MultipleAnswerQuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int>("QuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<int?>("SingleAnswerQuestionId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Text")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("MultipleAnswerQuestionId");
+
+                    b.HasIndex("QuestionId");
+
+                    b.HasIndex("SingleAnswerQuestionId");
+
+                    b.ToTable("AnswerVariant");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Completion", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<DateTime>("FinishedAt")
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("SurveyId")
+                        .HasColumnType("INTEGER");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SurveyId");
+
+                    b.ToTable("Completions");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionBase", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Discriminator")
+                        .IsRequired()
+                        .HasMaxLength(34)
+                        .HasColumnType("TEXT");
+
+                    b.Property<int>("SurveyId")
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SurveyId");
+
+                    b.ToTable("Questions");
+
+                    b.HasDiscriminator().HasValue("QuestionBase");
+
+                    b.UseTphMappingStrategy();
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Survey", b =>
+                {
+                    b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER");
+
+                    b.Property<string>("Description")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasColumnType("TEXT");
+
+                    b.HasKey("Id");
+
+                    b.ToTable("Surveys");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.MultipleAnswerQuestion", b =>
+                {
+                    b.HasBaseType("SurveyLib.Core.Models.QuestionBase");
+
+                    b.HasDiscriminator().HasValue("MultipleAnswerQuestion");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.SingleAnswerQuestion", b =>
+                {
+                    b.HasBaseType("SurveyLib.Core.Models.QuestionBase");
+
+                    b.HasDiscriminator().HasValue("SingleAnswerQuestion");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.TextQuestion", b =>
+                {
+                    b.HasBaseType("SurveyLib.Core.Models.QuestionBase");
+
+                    b.HasDiscriminator().HasValue("TextQuestion");
+                });
+
+            modelBuilder.Entity("GroupUser", b =>
+                {
+                    b.HasOne("SurveyBackend.Core.Models.Group", null)
+                        .WithMany()
+                        .HasForeignKey("GroupsId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("SurveyBackend.Core.Models.User", null)
+                        .WithMany()
+                        .HasForeignKey("UsersId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Answer", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.Completion", "Completion")
+                        .WithMany("Answers")
+                        .HasForeignKey("CompletionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("SurveyLib.Core.Models.QuestionBase", "Question")
+                        .WithMany("Answers")
+                        .HasForeignKey("QuestionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Completion");
+
+                    b.Navigation("Question");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.AnswerVariant", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.QuestionVariants.MultipleAnswerQuestion", null)
+                        .WithMany("AnswerVariants")
+                        .HasForeignKey("MultipleAnswerQuestionId");
+
+                    b.HasOne("SurveyLib.Core.Models.QuestionBase", "Question")
+                        .WithMany()
+                        .HasForeignKey("QuestionId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("SurveyLib.Core.Models.QuestionVariants.SingleAnswerQuestion", null)
+                        .WithMany("AnswerVariants")
+                        .HasForeignKey("SingleAnswerQuestionId");
+
+                    b.Navigation("Question");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Completion", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.Survey", "Survey")
+                        .WithMany("Completions")
+                        .HasForeignKey("SurveyId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Survey");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionBase", b =>
+                {
+                    b.HasOne("SurveyLib.Core.Models.Survey", "Survey")
+                        .WithMany("Questions")
+                        .HasForeignKey("SurveyId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Survey");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Completion", b =>
+                {
+                    b.Navigation("Answers");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionBase", b =>
+                {
+                    b.Navigation("Answers");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.Survey", b =>
+                {
+                    b.Navigation("Completions");
+
+                    b.Navigation("Questions");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.MultipleAnswerQuestion", b =>
+                {
+                    b.Navigation("AnswerVariants");
+                });
+
+            modelBuilder.Entity("SurveyLib.Core.Models.QuestionVariants.SingleAnswerQuestion", b =>
+                {
+                    b.Navigation("AnswerVariants");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Repositories/UserRepository.cs b/SurveyBackend/SurveyBackend.Infrastructure/Repositories/UserRepository.cs
index bd1980d..86124da 100644
--- a/SurveyBackend/SurveyBackend.Infrastructure/Repositories/UserRepository.cs
+++ b/SurveyBackend/SurveyBackend.Infrastructure/Repositories/UserRepository.cs
@@ -41,4 +41,9 @@ public class UserRepository : IUserRepository
         _context.Users.Remove(entity);
         await _context.SaveChangesAsync();
     }
+
+    public async Task<User?> GetUserByEmail(string email)
+    {
+        return await _context.Users.FirstOrDefaultAsync(u => u.Email == email);
+    }
 }
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/SurveyBackend.Infrastructure.csproj b/SurveyBackend/SurveyBackend.Infrastructure/SurveyBackend.Infrastructure.csproj
index 8d6e23a..e46ce0e 100644
--- a/SurveyBackend/SurveyBackend.Infrastructure/SurveyBackend.Infrastructure.csproj
+++ b/SurveyBackend/SurveyBackend.Infrastructure/SurveyBackend.Infrastructure.csproj
@@ -7,7 +7,11 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.3" />
+      <PackageReference Include="Microsoft.EntityFrameworkCore" Version="8.0.15" />
+      <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.15">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
       <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="7.1.2" />
     </ItemGroup>
 
@@ -16,4 +20,8 @@
       <ProjectReference Include="..\SurveyBackend.Core\SurveyBackend.Core.csproj" />
     </ItemGroup>
 
+    <ItemGroup>
+      <Folder Include="Data\Migrations\" />
+    </ItemGroup>
+
 </Project>
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/AuthOptions.cs b/SurveyBackend/SurveyBackend.Services/AuthOptions.cs
similarity index 96%
rename from SurveyBackend/SurveyBackend.Infrastructure/AuthOptions.cs
rename to SurveyBackend/SurveyBackend.Services/AuthOptions.cs
index cd379e8..7d92d6f 100644
--- a/SurveyBackend/SurveyBackend.Infrastructure/AuthOptions.cs
+++ b/SurveyBackend/SurveyBackend.Services/AuthOptions.cs
@@ -2,7 +2,7 @@ using System.Text;
 using Microsoft.Extensions.Configuration;
 using Microsoft.IdentityModel.Tokens;
 
-namespace SurveyBackend.Infrastructure;
+namespace SurveyBackend.Services;
 
 public static class AuthOptions
 {
diff --git a/SurveyBackend/SurveyBackend.Services/Exceptions/ConflictException.cs b/SurveyBackend/SurveyBackend.Services/Exceptions/ConflictException.cs
new file mode 100644
index 0000000..12d14ce
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/Exceptions/ConflictException.cs
@@ -0,0 +1,10 @@
+namespace SurveyBackend.Services.Exceptions;
+
+public class ConflictException : ServiceException
+{
+    public override int StatusCode => 409;
+
+    public ConflictException(string message) : base(message)
+    {
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Services/Exceptions/NotFoundException.cs b/SurveyBackend/SurveyBackend.Services/Exceptions/NotFoundException.cs
new file mode 100644
index 0000000..a5e5739
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/Exceptions/NotFoundException.cs
@@ -0,0 +1,10 @@
+namespace SurveyBackend.Services.Exceptions;
+
+public class NotFoundException : ServiceException
+{
+    public override int StatusCode => 404;
+
+    public NotFoundException(string message) : base(message)
+    {
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Services/Exceptions/ServiceException.cs b/SurveyBackend/SurveyBackend.Services/Exceptions/ServiceException.cs
new file mode 100644
index 0000000..30fb016
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/Exceptions/ServiceException.cs
@@ -0,0 +1,10 @@
+namespace SurveyBackend.Services.Exceptions;
+
+public abstract class ServiceException : Exception
+{
+    public abstract int StatusCode { get; }
+
+    protected ServiceException(string message) : base(message)
+    {
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Services/Exceptions/UnauthorizedException.cs b/SurveyBackend/SurveyBackend.Services/Exceptions/UnauthorizedException.cs
new file mode 100644
index 0000000..58ea510
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/Exceptions/UnauthorizedException.cs
@@ -0,0 +1,10 @@
+namespace SurveyBackend.Services.Exceptions;
+
+public class UnauthorizedException : ServiceException
+{
+    public override int StatusCode => 401;
+
+    public UnauthorizedException(string message) : base(message)
+    {
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Helpers/TokenHelper.cs b/SurveyBackend/SurveyBackend.Services/Helpers/TokenHelper.cs
similarity index 94%
rename from SurveyBackend/SurveyBackend.Infrastructure/Helpers/TokenHelper.cs
rename to SurveyBackend/SurveyBackend.Services/Helpers/TokenHelper.cs
index a52ae64..7c401a4 100644
--- a/SurveyBackend/SurveyBackend.Infrastructure/Helpers/TokenHelper.cs
+++ b/SurveyBackend/SurveyBackend.Services/Helpers/TokenHelper.cs
@@ -3,7 +3,7 @@ using System.Security.Claims;
 using Microsoft.IdentityModel.Tokens;
 using SurveyBackend.Core.Models;
 
-namespace SurveyBackend.Infrastructure.Helpers;
+namespace SurveyBackend.Services.Helpers;
 
 public class TokenHelper
 {
diff --git a/SurveyBackend/SurveyBackend.Services/Services/AuthorizationService.cs b/SurveyBackend/SurveyBackend.Services/Services/AuthorizationService.cs
new file mode 100644
index 0000000..772eb27
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/Services/AuthorizationService.cs
@@ -0,0 +1,45 @@
+using SurveyBackend.Core.Models;
+using SurveyBackend.Core.Services;
+using SurveyBackend.Services.Exceptions;
+using SurveyBackend.Services.Helpers;
+
+namespace SurveyBackend.Services.Services;
+
+public class AuthorizationService : IAuthorizationService
+{
+    private readonly IUserService _userService;
+    private readonly IPasswordHasher _passwordHasher;
+
+    public AuthorizationService(IUserService userService, IPasswordHasher passwordHasher)
+    {
+        _userService = userService;
+        _passwordHasher = passwordHasher;
+    }
+
+    public async Task<string> LogInUser(string email, string password)
+    {
+        var user = await _userService.GetUserByEmail(email);
+        if (!_passwordHasher.Verify(password, user.Password))
+        {
+            throw new UnauthorizedException("Password is incorrect.");
+        }
+
+        var token = TokenHelper.GetAuthToken(user);
+        return token;
+    }
+
+    public async Task<string> RegisterUser(User user)
+    {
+        var isEmailTaken = await _userService.IsEmailTaken(user.Email);
+        if (isEmailTaken)
+        {
+            throw new ConflictException("Email already exists");
+        }
+
+        user.Password = _passwordHasher.HashPassword(user.Password);
+
+        await _userService.CreateUserAsync(user);
+        var token = TokenHelper.GetAuthToken(user);
+        return token;
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Infrastructure/Services/Sha256PasswordHasher.cs b/SurveyBackend/SurveyBackend.Services/Services/Sha256PasswordHasher.cs
similarity index 95%
rename from SurveyBackend/SurveyBackend.Infrastructure/Services/Sha256PasswordHasher.cs
rename to SurveyBackend/SurveyBackend.Services/Services/Sha256PasswordHasher.cs
index f513cff..ed54508 100644
--- a/SurveyBackend/SurveyBackend.Infrastructure/Services/Sha256PasswordHasher.cs
+++ b/SurveyBackend/SurveyBackend.Services/Services/Sha256PasswordHasher.cs
@@ -1,6 +1,7 @@
 using System.Security.Cryptography;
+using SurveyBackend.Core.Services;
 
-namespace SurveyBackend.Infrastructure.Services;
+namespace SurveyBackend.Services.Services;
 
 public class Sha256PasswordHasher : IPasswordHasher
 {
diff --git a/SurveyBackend/SurveyBackend.Services/Services/UserService.cs b/SurveyBackend/SurveyBackend.Services/Services/UserService.cs
new file mode 100644
index 0000000..9c52a64
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/Services/UserService.cs
@@ -0,0 +1,31 @@
+using SurveyBackend.Core.Models;
+using SurveyBackend.Core.Repositories;
+using SurveyBackend.Core.Services;
+using SurveyBackend.Services.Exceptions;
+
+namespace SurveyBackend.Services.Services;
+
+public class UserService : IUserService
+{
+    private readonly IUserRepository _userRepository;
+
+    public UserService(IUserRepository userRepository)
+    {
+        _userRepository = userRepository;
+    }
+
+    public async Task<User> GetUserByEmail(string email)
+    {
+        return await _userRepository.GetUserByEmail(email) ?? throw new NotFoundException("Email not found");
+    }
+
+    public async Task<bool> IsEmailTaken(string email)
+    {
+        return await _userRepository.GetUserByEmail(email) != null;
+    }
+
+    public async Task CreateUserAsync(User user)
+    {
+        await _userRepository.AddAsync(user);
+    }
+}
\ No newline at end of file
diff --git a/SurveyBackend/SurveyBackend.Services/SurveyBackend.Services.csproj b/SurveyBackend/SurveyBackend.Services/SurveyBackend.Services.csproj
new file mode 100644
index 0000000..5765782
--- /dev/null
+++ b/SurveyBackend/SurveyBackend.Services/SurveyBackend.Services.csproj
@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\SurveyBackend.Core\SurveyBackend.Core.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="7.1.2" />
+    </ItemGroup>
+
+</Project>
diff --git a/SurveyBackend/SurveyBackend.sln b/SurveyBackend/SurveyBackend.sln
index bbfd9ab..56dba6f 100644
--- a/SurveyBackend/SurveyBackend.sln
+++ b/SurveyBackend/SurveyBackend.sln
@@ -10,6 +10,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SurveyLib.Infrastructure.EF
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SurveyLib.Core", "..\SurveyLib\SurveyLib.Core\SurveyLib.Core.csproj", "{C17C405B-37CF-48E6-AA44-44B878F4DE56}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SurveyBackend.Services", "SurveyBackend.Services\SurveyBackend.Services.csproj", "{3CDA6495-4FB2-4F07-8B2F-15BFD2A35181}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -36,5 +38,9 @@ Global
 		{C17C405B-37CF-48E6-AA44-44B878F4DE56}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C17C405B-37CF-48E6-AA44-44B878F4DE56}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C17C405B-37CF-48E6-AA44-44B878F4DE56}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3CDA6495-4FB2-4F07-8B2F-15BFD2A35181}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3CDA6495-4FB2-4F07-8B2F-15BFD2A35181}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3CDA6495-4FB2-4F07-8B2F-15BFD2A35181}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3CDA6495-4FB2-4F07-8B2F-15BFD2A35181}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal
diff --git a/SurveyLib b/SurveyLib
index 7bbc78f..fe2735d 160000
--- a/SurveyLib
+++ b/SurveyLib
@@ -1 +1 @@
-Subproject commit 7bbc78fbd7eef3bb2497b966ea73eba31aa7032c
+Subproject commit fe2735da5040501f143526a8c1af19c8023f6368