diff --git a/backend/CircleForms.Tests/CircleForms.Tests.csproj b/backend/CircleForms.Tests/CircleForms.Tests.csproj
new file mode 100644
index 00000000..e5793e24
--- /dev/null
+++ b/backend/CircleForms.Tests/CircleForms.Tests.csproj
@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Moq" Version="4.18.1" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="3.1.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Folder Include="Integration\" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\CircleForms\CircleForms.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/backend/CircleForms.Tests/Unit/Database/Services/RedisCacheRepositoryTests.cs b/backend/CircleForms.Tests/Unit/Database/Services/RedisCacheRepositoryTests.cs
new file mode 100644
index 00000000..11b1e0d4
--- /dev/null
+++ b/backend/CircleForms.Tests/Unit/Database/Services/RedisCacheRepositoryTests.cs
@@ -0,0 +1,180 @@
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using CircleForms.Database.Models.Users;
+using CircleForms.Database.Services;
+using CircleForms.Database.Services.Extensions;
+using CircleForms.Tests.Utils;
+using Microsoft.Extensions.Logging.Abstractions;
+using MongoDB.Bson;
+using Moq;
+using StackExchange.Redis;
+using Xunit;
+using JsonConvert = Newtonsoft.Json.JsonConvert;
+
+namespace CircleForms.Tests.Unit.Database.Services
+{
+    public class RedisCacheRepositoryTests
+    {
+        private readonly RedisCacheRepository _cache;
+        private readonly Mock<IDatabase> _redisDatabaseMock;
+
+        public RedisCacheRepositoryTests()
+        {
+            _redisDatabaseMock = new Mock<IDatabase>(MockBehavior.Strict);
+
+            var redisMock = new Mock<IConnectionMultiplexer>();
+            redisMock.Setup(x => x.GetDatabase(It.IsAny<int>(), It.IsAny<object>())).Returns(_redisDatabaseMock.Object);
+
+            _cache = new RedisCacheRepository(redisMock.Object, MappingHelper.CreateMapper(),
+                new NullLogger<RedisCacheRepository>());
+        }
+
+        [Fact]
+        public async Task IncrementAnswersUsesCorrectId()
+        {
+            const string id = "123456";
+
+            _redisDatabaseMock
+                .Setup(x => x.StringIncrementAsync(It.Is<RedisKey>(y => y == id.ToPostAnswersCount()), It.IsAny<long>(),
+                    It.IsAny<CommandFlags>()))
+                .ReturnsAsync(1);
+
+            await _cache.IncrementAnswers(id);
+        }
+
+        [Fact]
+        public async Task PinPostAddsPostToTheSet()
+        {
+            var postId = new Guid().ToString();
+
+            _redisDatabaseMock
+                .Setup(x => x.KeyExists(It.Is<RedisKey>(y => y == postId.ToPostId()), It.IsAny<CommandFlags>()))
+                .Returns(true);
+
+            _redisDatabaseMock
+                .Setup(x => x.SetAddAsync(It.Is<RedisKey>(y => y == "posts:pinned"),
+                    It.Is<RedisValue>(y => y == postId.ToPostId()), It.IsAny<CommandFlags>()))
+                .ReturnsAsync(true);
+
+            var result = await _cache.PinPost(postId);
+
+            Assert.True(result);
+            _redisDatabaseMock.Verify();
+        }
+
+        [Fact]
+        public async Task PinPostDoesntAddPostToTheSetWhenItDoesntExist()
+        {
+            var postId = new Guid().ToString();
+
+            _redisDatabaseMock
+                .Setup(x => x.KeyExists(It.Is<RedisKey>(y => y == postId.ToPostId()), It.IsAny<CommandFlags>()))
+                .Returns(false);
+
+            var result = await _cache.PinPost(postId);
+
+            Assert.False(result);
+            _redisDatabaseMock.Verify();
+        }
+
+        [Fact]
+        public async Task AddUserAddsCorrectData()
+        {
+            var user = new User
+            {
+                ID = "123456",
+                Discord = "Test#7270",
+                Osu = new BsonDocument(new Dictionary<string, object>
+                {
+                    { "Username", "VsevolodVolkov" },
+                    { "AvatarUrl", "https://a.ppy.sh/123456" }
+                })
+            };
+
+            var expectedRedisUser = JsonConvert.SerializeObject(new UserMinimalRedis
+            {
+                ID = user.ID,
+                Discord = user.Discord,
+                Username = user.Osu["Username"].ToString(),
+                AvatarUrl = user.Osu["AvatarUrl"].ToString()
+            });
+
+            _redisDatabaseMock
+                .Setup(x => x.SetAddAsync(It.Is<RedisKey>(y => y == "user_ids"), It.Is<RedisValue>(y => y == user.ID),
+                    It.IsAny<CommandFlags>()))
+                .ReturnsAsync(true);
+
+            _redisDatabaseMock
+                .Setup(x => x.StringSetAsync(It.Is<RedisKey>(y => y == user.ID.ToUserId()),
+                    It.Is<RedisValue>(y => y == expectedRedisUser),
+                    It.IsAny<TimeSpan?>(), It.IsAny<When>(), It.IsAny<CommandFlags>()))
+                .ReturnsAsync(true);
+
+            await _cache.AddUser(user);
+
+            _redisDatabaseMock.Verify();
+        }
+
+        [Fact]
+        public async Task GetMinimalUserReturnsUserOnCorrectId()
+        {
+            var user = new UserMinimalRedis
+            {
+                ID = "123456",
+                Username = "VsevolodVolkov",
+                AvatarUrl = "https://a.ppy.sh/123456",
+                Discord = "Test#7270"
+            };
+
+            _redisDatabaseMock
+                .Setup(x => x.StringGetAsync(It.Is<RedisKey>(y => y == user.ID.ToUserId()), It.IsAny<CommandFlags>()))
+                .ReturnsAsync(new RedisValue(JsonConvert.SerializeObject(user)));
+
+            var result = await _cache.GetMinimalUser(user.ID);
+
+            Assert.NotNull(result);
+            Assert.Equal(user.ID, result.ID);
+            Assert.Equal(user.Username, result.Username);
+            Assert.Equal(user.AvatarUrl, result.AvatarUrl);
+            Assert.Equal(user.Discord, result.Discord);
+        }
+
+        [Fact]
+        public async Task GetMinimalUserReturnsNullOnIncorrectId()
+        {
+            var user = new UserMinimalRedis
+            {
+                ID = "123456",
+                Username = "VsevolodVolkov",
+                AvatarUrl = "https://a.ppy.sh/123456",
+                Discord = "Test#7270"
+            };
+
+            _redisDatabaseMock
+                .Setup(x => x.StringGetAsync(It.Is<RedisKey>(y => y == user.ID.ToUserId()), It.IsAny<CommandFlags>()))
+                .ReturnsAsync(new RedisValue());
+
+            var result = await _cache.GetMinimalUser(user.ID);
+
+            Assert.Null(result);
+        }
+
+        [Fact]
+        public async Task RemoveUserUsesCorrectIds()
+        {
+            const string id = "123456";
+
+            _redisDatabaseMock
+                .Setup(x => x.KeyDeleteAsync(It.Is<RedisKey>(y => y == id.ToUserId()), It.IsAny<CommandFlags>()))
+                .ReturnsAsync(true);
+
+            _redisDatabaseMock
+                .Setup(x => x.SetRemoveAsync(It.Is<RedisKey>(y => y == "user_ids"), It.Is<RedisValue>(y => y == id), It.IsAny<CommandFlags>()))
+                .ReturnsAsync(true);
+
+            await _cache.RemoveUser(id);
+        }
+    }
+}
diff --git a/backend/CircleForms.Tests/Utils/MappingHelper.cs b/backend/CircleForms.Tests/Utils/MappingHelper.cs
new file mode 100644
index 00000000..83bbd310
--- /dev/null
+++ b/backend/CircleForms.Tests/Utils/MappingHelper.cs
@@ -0,0 +1,17 @@
+using FastExpressionCompiler;
+using Mapster;
+using MapsterMapper;
+
+namespace CircleForms.Tests.Utils
+{
+    internal static class MappingHelper
+    {
+        public static IMapper CreateMapper()
+        {
+            TypeAdapterConfig.GlobalSettings.Scan(typeof(Program).Assembly);
+            TypeAdapterConfig.GlobalSettings.Compiler = x => x.CompileFast();
+
+            return new Mapper();
+        }
+    }
+}
diff --git a/backend/CircleForms/Database/Models/Users/User.cs b/backend/CircleForms/Database/Models/Users/User.cs
index a8feb7b4..57c8bd71 100644
--- a/backend/CircleForms/Database/Models/Users/User.cs
+++ b/backend/CircleForms/Database/Models/Users/User.cs
@@ -12,8 +12,12 @@ public class User : IEntity
 {
     public User()
     {
-        this.InitOneToMany(() => PostsRelation);
-        this.InitOneToMany(() => Answers);
+        // DB inits can't be done in unit testing due to how MongoDB.Entities database initialization works
+        if (!UnitTestDetector.IsRunningFromXUnit)
+        {
+            this.InitOneToMany(() => PostsRelation);
+            this.InitOneToMany(() => Answers);
+        }
     }
 
     [Field("token")]
diff --git a/backend/CircleForms/Database/Services/RedisCacheRepository.cs b/backend/CircleForms/Database/Services/RedisCacheRepository.cs
index eb192a3b..3ecd38fe 100644
--- a/backend/CircleForms/Database/Services/RedisCacheRepository.cs
+++ b/backend/CircleForms/Database/Services/RedisCacheRepository.cs
@@ -70,9 +70,16 @@ public async Task<bool> UserExists(string id)
 
     public async Task AddUser(User user)
     {
-        await _redis.SetAddAsync(_userIds, user.ID);
+        if (!await _redis.SetAddAsync(_userIds, user.ID))
+        {
+            _logger.LogError("Could not post {@User} to the redis userid cache", user.ID);
+        }
+
         var cachedUser = _mapper.Map<UserMinimalRedis>(user);
-        await _redis.StringSetAsync(user.ID.ToUserId(), JsonConvert.SerializeObject(cachedUser, Formatting.None));
+        if (!await _redis.StringSetAsync(user.ID.ToUserId(), JsonConvert.SerializeObject(cachedUser, Formatting.None)))
+        {
+            _logger.LogError("Could not post {@User} to the redis user cache", user);
+        }
     }
 
     public async Task<UserMinimalRedis> GetMinimalUser(string id)
diff --git a/backend/CircleForms/UnitTestDetector.cs b/backend/CircleForms/UnitTestDetector.cs
new file mode 100644
index 00000000..3f2d0b1a
--- /dev/null
+++ b/backend/CircleForms/UnitTestDetector.cs
@@ -0,0 +1,25 @@
+using System;
+
+namespace CircleForms;
+
+/// <summary>
+/// This exists ONLY for MongoDB.Entities-based models and MUST NOT be used anywhere else.
+/// Doing workarounds for unit testing is a very very bad design, but unfortunately we can't avoid it here.
+/// </summary>
+public static class UnitTestDetector
+{
+    static UnitTestDetector()
+    {
+        foreach (var assem in AppDomain.CurrentDomain.GetAssemblies())
+        {
+            if (assem.FullName != null &&
+                assem.FullName.ToLowerInvariant().StartsWith("xunit"))
+            {
+                IsRunningFromXUnit = true;
+                break;
+            }
+        }
+    }
+
+    public static bool IsRunningFromXUnit { get; }
+}