diff --git a/Govor.API.Tests/IntegrationTests/EF/Repositories/UsersRepositoryTests.cs b/Govor.API.Tests/IntegrationTests/EF/Repositories/UsersRepositoryTests.cs
index be69968..c70dcff 100644
--- a/Govor.API.Tests/IntegrationTests/EF/Repositories/UsersRepositoryTests.cs
+++ b/Govor.API.Tests/IntegrationTests/EF/Repositories/UsersRepositoryTests.cs
@@ -3,6 +3,7 @@ using Govor.Core.Infrastructure.Validators;
 using Govor.Core.Models;
 using Govor.Data;
 using Govor.Data.Repositories;
+using Govor.Data.Repositories.Exceptions;
 using Microsoft.EntityFrameworkCore;
 
 namespace Govor.API.Tests.IntegrationTests.EF.Repositories;
@@ -53,5 +54,75 @@ public class UsersRepositoryTests
         Assert.That(result.Count, Is.EqualTo(users.Count));
         Assert.That(result.Select(u => u.Id), Is.EquivalentTo(users.Select(u => u.Id)));
         Assert.That(result.Select(u => u.Username), Is.EquivalentTo(users.Select(u => u.Username)));
-    } 
+    }
+
+    [Test]
+    public async Task Given_ValidUserId_When_FindById_Then_Returns_User()
+    {
+        // Arrange
+        var user  = _fixture.Create<User>();
+        await using var context = new GovorDbContext(_options);
+        var userRepository = new UsersRepository(context, _userValidator);
+        
+        context.Users.Add(user);
+        await context.SaveChangesAsync();
+        
+        // Act 
+        var result = await userRepository.FindById(user.Id);
+        
+        // Assert 
+        Assert.That(result, Is.Not.Null);
+        Assert.That(result.Username, Is.EqualTo(user.Username));
+        Assert.That(result.Id, Is.EqualTo(user.Id));
+    }
+    
+    [Test]
+    public async Task Given_InvalidUserId_When_FindById_Should_Throw_NotFoundException()
+    {
+        // Arrange 
+        var id = Guid.NewGuid();
+        
+        await using var context = new GovorDbContext(_options);
+        var userRepository = new UsersRepository(context, _userValidator);
+        
+        // Act & Assert  
+        Assert.ThrowsAsync<NotFoundByKeyException<Guid>>(async () => await userRepository.FindById(id));
+    }
+    
+    [Test]
+    public async Task Given_RangeValidUserId_When_FindByRangeId_Then_Returns_Users()
+    {
+        // Arrange 
+        var random = new Random();
+        var users = _fixture.CreateMany<User>(random.Next(2, 10)).ToList();
+        
+        await using var context = new GovorDbContext(_options);
+        var userRepository = new UsersRepository(context, _userValidator);
+        
+        context.Users.AddRange(users);
+        await context.SaveChangesAsync();
+        
+        // Act 
+        var result = await userRepository.FindByRangeId(users.Select(u => u.Id));
+        
+        // Assert 
+        Assert.That(result, Is.Not.Null);
+        Assert.That(result.Count, Is.EqualTo(users.Count));
+        Assert.That(result.Select(r => r.Id), Is.EquivalentTo(users.Select(u => u.Id)));
+        Assert.That(result.Select(u => u.Username), Is.EquivalentTo(users.Select(u => u.Username)));
+    }
+    
+    [Test]
+    public async Task Given_InvalidRangeId_When_FindByRangeId_Should_Throw_NotFoundException()
+    {
+        // Arrange 
+        var random = new Random();
+        var ids = _fixture.CreateMany<Guid>(random.Next(2, 10)).ToList();
+        
+        await using var context = new GovorDbContext(_options);
+        var userRepository = new UsersRepository(context, _userValidator);
+        
+        // Act & Assert 
+        Assert.ThrowsAsync<NotFoundByKeyException<IEnumerable<Guid>>>(async () => await userRepository.FindByRangeId(ids));
+    }
 }
\ No newline at end of file
diff --git a/Govor.Core/Govor.Core.csproj b/Govor.Core/Govor.Core.csproj
index b9fad79..71fa877 100644
--- a/Govor.Core/Govor.Core.csproj
+++ b/Govor.Core/Govor.Core.csproj
@@ -10,4 +10,8 @@
       <Folder Include="DTOs\" />
     </ItemGroup>
 
+    <ItemGroup>
+      <PackageReference Include="Microsoft.EntityFrameworkCore" Version="9.0.6" />
+    </ItemGroup>
+
 </Project>
diff --git a/Govor.Core/Infrastructure/Extensions/QueryableExtensions.cs b/Govor.Core/Infrastructure/Extensions/QueryableExtensions.cs
new file mode 100644
index 0000000..e380f41
--- /dev/null
+++ b/Govor.Core/Infrastructure/Extensions/QueryableExtensions.cs
@@ -0,0 +1,13 @@
+using Microsoft.EntityFrameworkCore;
+
+namespace Govor.Core.Infrastructure.Extensions;
+
+public static class QueryableExtensions
+{
+    public static async Task<List<T>> ToListOrThrowIfEmpty<T>(this IQueryable<T> query, Exception ex)
+    {
+        var list = await query.ToListAsync();
+        if (list.Count == 0) throw ex;
+        return list;
+    }
+}
diff --git a/Govor.Core/Repositories/IUsersReader.cs b/Govor.Core/Repositories/IUsersReader.cs
index 6811e95..e8ec196 100644
--- a/Govor.Core/Repositories/IUsersReader.cs
+++ b/Govor.Core/Repositories/IUsersReader.cs
@@ -6,9 +6,8 @@ public interface IUsersReader
 {
     public Task<IEnumerable<User>> GetAll();
     public Task<User> FindById(Guid id);
-    public Task<IEnumerable<User>> FindByRangeId(IEnumerable<Guid> ids);
-    public Task<User> FindByUsername(string username);
-    public Task<IEnumerable<User>> FindByRangeUsername(IEnumerable<string> usernames);
-    
-    public Task<IEnumerable<User>> FindUsersByCreatedDate(DateOnly createdDate);
+    public Task<List<User>> FindByRangeId(IEnumerable<Guid> ids);
+    public Task<List<User>> FindUsersByName(string username);
+    public Task<List<User>> FindByRangeUsername(IEnumerable<string> usernames);
+    public Task<List<User>> FindUsersByCreatedDate(DateOnly createdDate);
 }
\ No newline at end of file
diff --git a/Govor.Data/Repositories/Exceptions/NotFoundByKeyException.cs b/Govor.Data/Repositories/Exceptions/NotFoundByKeyException.cs
new file mode 100644
index 0000000..08f6c8b
--- /dev/null
+++ b/Govor.Data/Repositories/Exceptions/NotFoundByKeyException.cs
@@ -0,0 +1,14 @@
+namespace Govor.Data.Repositories.Exceptions;
+
+public class NotFoundByKeyException<T> : NotFoundException
+{
+    public NotFoundByKeyException(T key) 
+        : base($"Not found object by {key}"){}
+
+    public NotFoundByKeyException(T id, string message) 
+        : base($"Not found object by {id}. Message: " + message) {}
+    
+    public NotFoundByKeyException(string message, Exception innerException) : base(message, innerException)
+    {
+    }
+}
\ No newline at end of file
diff --git a/Govor.Data/Repositories/Exceptions/NotFoundException.cs b/Govor.Data/Repositories/Exceptions/NotFoundException.cs
new file mode 100644
index 0000000..dc60ca5
--- /dev/null
+++ b/Govor.Data/Repositories/Exceptions/NotFoundException.cs
@@ -0,0 +1,11 @@
+using Govor.Core;
+
+namespace Govor.Data.Repositories.Exceptions;
+
+public class NotFoundException : GovorCoreException
+{
+    public NotFoundException(string message)
+        : base(message) {}
+    public NotFoundException(string message, Exception innerException) 
+        : base(message, innerException){}
+}
\ No newline at end of file
diff --git a/Govor.Data/Repositories/UsersRepository.cs b/Govor.Data/Repositories/UsersRepository.cs
index 303c368..a0feee6 100644
--- a/Govor.Data/Repositories/UsersRepository.cs
+++ b/Govor.Data/Repositories/UsersRepository.cs
@@ -1,6 +1,8 @@
+using Govor.Core.Infrastructure.Extensions;
 using Govor.Core.Infrastructure.Validators;
 using Govor.Core.Models;
 using Govor.Core.Repositories;
+using Govor.Data.Repositories.Exceptions;
 using Microsoft.EntityFrameworkCore;
 
 namespace Govor.Data.Repositories;
@@ -23,27 +25,39 @@ public class UsersRepository : IUsersRepository
             .ToListAsync();
     }
 
-    public Task<User> FindById(Guid id)
+    public async Task<User> FindById(Guid id)
     {
-        throw new NotImplementedException();
+        return await _context.Users
+            .AsNoTracking()
+            .FirstOrDefaultAsync(x => x.Id == id)
+               ?? throw new NotFoundByKeyException<Guid>(id, "User with given id does not exist");
     }
 
-    public Task<IEnumerable<User>> FindByRangeId(IEnumerable<Guid> ids)
+    public async Task<List<User>> FindByRangeId(IEnumerable<Guid> ids)
     {
-        throw new NotImplementedException();
+        return await _context.Users
+            .AsNoTracking()
+            .Where(x => ids.Contains(x.Id))
+            .ToListOrThrowIfEmpty(new NotFoundByKeyException<IEnumerable<Guid>>(ids,"Users with given ids not found"));
+    }
+    
+    public async Task<List<User>> FindUsersByName(string username)
+    {
+        return await _context.Users
+            .AsNoTracking()
+            .Where(x => x.Username == username)
+            .ToListOrThrowIfEmpty(new NotFoundByKeyException<string>(username, "Users with given username not found"));
+    }
+    
+    public async Task<List<User>> FindByRangeUsername(IEnumerable<string> usernames)
+    {
+        return await _context.Users
+            .AsNoTracking()
+            .Where(x => usernames.Contains(x.Username))
+            .ToListOrThrowIfEmpty(new NotFoundByKeyException<IEnumerable<string>>(usernames, "Users with given usernames not found"));
     }
 
-    public Task<User> FindByUsername(string username)
-    {
-        throw new NotImplementedException();
-    }
-
-    public Task<IEnumerable<User>> FindByRangeUsername(IEnumerable<string> usernames)
-    {
-        throw new NotImplementedException();
-    }
-
-    public Task<IEnumerable<User>> FindUsersByCreatedDate(DateOnly createdDate)
+    public Task<List<User>> FindUsersByCreatedDate(DateOnly createdDate)
     {
         throw new NotImplementedException();
     }