diff --git a/.github/workflows/build-test-ci.yml b/.github/workflows/build-test-ci.yml
new file mode 100644
index 0000000..594f390
--- /dev/null
+++ b/.github/workflows/build-test-ci.yml
@@ -0,0 +1,30 @@
+name: Build / unit tests
+
+on:
+  push:
+    branches:
+      - main 
+  pull_request:
+    branches:
+      - main
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest  
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 6.x 
+
+    - name: Restore dependencies
+      run: dotnet restore
+
+    - name: Build
+      run: dotnet build --configuration Release 
+
+    - name: Run tests
+      run: dotnet test --configuration Release --no-build
\ No newline at end of file
diff --git a/NorthwindCRUD.Tests/BaseFixture.cs b/NorthwindCRUD.Tests/BaseFixture.cs
new file mode 100644
index 0000000..97d4775
--- /dev/null
+++ b/NorthwindCRUD.Tests/BaseFixture.cs
@@ -0,0 +1,50 @@
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using NorthwindCRUD.Helpers;
+using System.Data.Common;
+
+namespace NorthwindCRUD.Tests
+{
+    public class BaseFixture
+    {
+        private DbConnection? connection;
+
+        protected DataContext GetInMemoryDatabaseContext()
+        {
+            if (connection == null)
+            {
+                connection = CreateDbConnection();
+                var context = CreateInMemoryDatabaseContext(connection);
+                DBSeeder.Seed(context);
+                return context;
+            }
+            else
+            {
+                // Create a new Context on already initialized DB connection
+                return CreateInMemoryDatabaseContext(connection);
+            }
+        }
+
+        protected static DbConnection CreateDbConnection()
+        {
+            var connection = new SqliteConnection("DataSource=:memory:");
+            connection.Open();
+            return connection;
+        }
+
+
+        protected static DataContext CreateInMemoryDatabaseContext(DbConnection connection)
+        {
+            var options = new DbContextOptionsBuilder<DataContext>()
+                .UseSqlite(connection)
+                .EnableSensitiveDataLogging()
+
+                // Uncomment the following line for detailed sql EF logs.
+                // .EnableDetailedErrors().LogTo(Console.WriteLine, LogLevel.Debug)
+                .Options;
+
+            return new DataContext(options);
+        }
+
+    }
+}
diff --git a/NorthwindCRUD.Tests/CategroyServiceFixture.cs b/NorthwindCRUD.Tests/CategroyServiceFixture.cs
new file mode 100644
index 0000000..ef0b5d9
--- /dev/null
+++ b/NorthwindCRUD.Tests/CategroyServiceFixture.cs
@@ -0,0 +1,82 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using NorthwindCRUD.Services;
+using NorthwindCRUD.Models.DbModels;
+
+namespace NorthwindCRUD.Tests
+{
+    [TestClass]
+    public class CategoryServiceFixture : BaseFixture
+    {
+        private CategoryService categoryService;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            DataContext context = GetInMemoryDatabaseContext();
+            categoryService = new CategoryService(context);
+        }
+
+        [TestMethod]
+        public void ShouldCreateCategory()
+        {
+            var category = new CategoryDb
+            {
+                Name = "New Category",
+                Description = "New Category Description"
+            };
+
+            var createdCategory = categoryService.Create(category);
+
+            var result = categoryService.GetById(createdCategory.CategoryId);
+
+            Assert.IsNotNull(createdCategory);
+            Assert.AreEqual(category.Name, result.Name);
+            Assert.AreEqual(category.Description, result.Description);
+        }
+
+        [TestMethod]
+        public void ShouldUpdateCategory()
+        {
+            var category = new CategoryDb
+            {
+                Name = "New Category",
+                Description = "New Category Description"
+            };
+            var createdCategory = categoryService.Create(category);
+
+            createdCategory.Name = "Updated Category";
+            createdCategory.Description = "Updated Description";
+            var updatedCategory = categoryService.Update(createdCategory);
+
+            Assert.IsNotNull(updatedCategory);
+            Assert.AreEqual("Updated Category", updatedCategory.Name);
+            Assert.AreEqual("Updated Description", updatedCategory.Description);
+        }
+
+        [TestMethod]
+        public void ShouldDeleteCategory()
+        {
+            var category = new CategoryDb
+            {
+                Name = "New Category",
+                Description = "New Category Description"
+            };
+            
+            var createdCategory = categoryService.Create(category);
+
+            categoryService.Delete(createdCategory.CategoryId);
+            var deletedCategory = categoryService.GetById(createdCategory.CategoryId);
+
+            Assert.IsNull(deletedCategory);
+        }
+
+        [TestMethod]
+        public void ShouldReturnAllCategories()
+        {
+            var result = categoryService.GetAll();
+
+            Assert.IsNotNull(result);
+            Assert.IsTrue(result.Count() > 0);
+        }
+    }
+}
\ No newline at end of file
diff --git a/NorthwindCRUD.Tests/CustomerServiceFixture.cs b/NorthwindCRUD.Tests/CustomerServiceFixture.cs
new file mode 100644
index 0000000..f04e388
--- /dev/null
+++ b/NorthwindCRUD.Tests/CustomerServiceFixture.cs
@@ -0,0 +1,77 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using NorthwindCRUD.Services;
+using NorthwindCRUD.Models.DbModels;
+
+namespace NorthwindCRUD.Tests
+{
+    [TestClass]
+    public class CustomerServiceFixture : BaseFixture
+    {
+        private CustomerService customerService;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            DataContext context = GetInMemoryDatabaseContext();
+            customerService = new CustomerService(context);
+        }
+
+        [TestMethod]
+        public void ShouldCreateCustomer()
+        {
+            var address = new AddressDb
+            {
+                Street = "6955 Union Park Center Suite 500",
+                City = "Midvale",
+                PostalCode = "84047",
+                Region = "",
+                Country = "USA",
+                Phone = "(800) 231-8588",
+            };
+
+            var customer = new CustomerDb
+            {
+                CustomerId = "12345",
+                CompanyName = "Infragistics",
+                ContactName = "Maria Anders",
+                ContactTitle = "Sales Representative",
+                Address = address,
+            };
+
+            var createdCustomer = customerService.Create(customer);
+            
+            Assert.IsNotNull(createdCustomer);
+            Assert.AreEqual(customer.CompanyName, createdCustomer.CompanyName);
+            Assert.AreEqual(customer.ContactName, createdCustomer.ContactName);
+            Assert.AreEqual(customer.ContactTitle, createdCustomer.ContactTitle);
+            Assert.AreEqual(customer.Address.Street, createdCustomer.Address.Street);
+            Assert.AreEqual(customer.Address.City, createdCustomer.Address.City);
+            Assert.AreEqual(customer.Address.PostalCode, createdCustomer.Address.PostalCode);
+            Assert.AreEqual(customer.Address.Country, createdCustomer.Address.Country);
+            Assert.AreEqual(customer.Address.Phone, createdCustomer.Address.Phone);
+        }
+
+        [TestMethod]
+        public void ShouldUpdateEmployee()
+        {
+        }
+
+        [TestMethod]
+        public void ShouldDeleteEmployee()
+        {
+        }
+
+        [TestMethod]
+        public void ShouldReturnAllCustomers()
+        {
+            var result = customerService.GetAll();
+            Assert.IsNotNull(result);
+            Assert.IsTrue(result.Count() > 0);
+        }
+
+        [TestMethod]
+        public void ShouldReturnEmployeesByReportsTo()
+        {            
+        }
+    }
+}
\ No newline at end of file
diff --git a/NorthwindCRUD.Tests/EmployeeServiceFixture.cs b/NorthwindCRUD.Tests/EmployeeServiceFixture.cs
new file mode 100644
index 0000000..da7bfaa
--- /dev/null
+++ b/NorthwindCRUD.Tests/EmployeeServiceFixture.cs
@@ -0,0 +1,139 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using NorthwindCRUD.Services;
+using NorthwindCRUD.Models.DbModels;
+
+namespace NorthwindCRUD.Tests
+{
+    [TestClass]
+    public class EmployeeServiceFixture : BaseFixture
+    {
+        private EmployeeService employeeService;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            DataContext context = GetInMemoryDatabaseContext();
+            employeeService = new EmployeeService(context);
+        }
+
+        [TestMethod]
+        public void ShouldCreateEmployee()
+        {
+            var employee = new EmployeeDb
+            {
+                FirstName = "John",
+                LastName = "Doe",
+                Title = "Manager"
+            };
+
+            var createdEmployee = employeeService.Create(employee);
+
+            Assert.IsNotNull(createdEmployee);
+            Assert.AreEqual(employee.FirstName, createdEmployee.FirstName);
+            Assert.AreEqual(employee.LastName, createdEmployee.LastName);
+            Assert.AreEqual(employee.Title, createdEmployee.Title);
+        }
+
+        [TestMethod]
+        public void ShouldUpdateEmployee()
+        {
+            var employee = new EmployeeDb
+            {
+                FirstName = "John",
+                LastName = "Doe",
+                Title = "Manager"
+            };
+            var createdEmployee = employeeService.Create(employee);
+
+            createdEmployee.Title = "Director";
+            var updatedEmployee = employeeService.Update(createdEmployee);
+
+            Assert.IsNotNull(updatedEmployee);
+            Assert.AreEqual("Director", updatedEmployee.Title);
+        }
+
+        [TestMethod]
+        public void ShouldDeleteEmployee()
+        {
+            var employee = new EmployeeDb
+            {
+                FirstName = "John",
+                LastName = "Doe",
+                Title = "Manager"
+            };
+            var createdEmployee = employeeService.Create(employee);
+
+            employeeService.Delete(createdEmployee.EmployeeId);
+            var deletedEmployee = employeeService.GetById(createdEmployee.EmployeeId);
+            
+            Assert.IsNull(deletedEmployee);
+        }
+
+        [TestMethod]
+        public void ShouldReturnAllEmployees()
+        {
+            var result = employeeService.GetAll();
+
+            Assert.IsNotNull(result);
+            Assert.IsTrue(result.Count() > 0);
+        }
+
+        [TestMethod]
+        public void ShouldReturnEmployeesByReportsTo()
+        {            
+            var manager = new EmployeeDb
+            {
+                FirstName = "Manager",
+                LastName = "Doe",
+                Title = "Manager"
+            };
+
+            var createdManager = employeeService.Create(manager);
+            var employee1 = new EmployeeDb
+            {
+                FirstName = "Employee1",
+                LastName = "Smith",
+                Title = "Employee",
+                ReportsTo = createdManager.EmployeeId
+            };
+
+            var employee2 = new EmployeeDb
+            {
+                FirstName = "Employee2",
+                LastName = "Johnson",
+                Title = "Employee",
+                ReportsTo = createdManager.EmployeeId
+            };
+
+
+            var createdEmployee1 = employeeService.Create(employee1);
+            var createdEmployee2 = employeeService.Create(employee2);
+
+            
+            var result = employeeService.GetEmployeesByReportsTo(createdManager.EmployeeId);
+            
+            Assert.IsNotNull(result);
+            Assert.AreEqual(2, result.Count());
+            Assert.IsTrue(result.All(e => e.ReportsTo == createdManager.EmployeeId));
+        }
+
+        [TestMethod]
+        public void ShouldReturnEmployeeById()
+        {
+            var employee = new EmployeeDb
+            {
+                FirstName = "John",
+                LastName = "Doe",
+                Title = "Manager"
+            };
+            var createdEmployee = employeeService.Create(employee);
+
+            var result = employeeService.GetById(createdEmployee.EmployeeId);
+
+            Assert.IsNotNull(result);
+            Assert.AreEqual("John", result.FirstName);
+            Assert.AreEqual("Doe", result.LastName);
+            Assert.AreEqual("Manager", result.Title);
+        }
+    }
+}
\ No newline at end of file
diff --git a/NorthwindCRUD.Tests/EmployeeTerritoryServiceFixture.cs b/NorthwindCRUD.Tests/EmployeeTerritoryServiceFixture.cs
new file mode 100644
index 0000000..154f67a
--- /dev/null
+++ b/NorthwindCRUD.Tests/EmployeeTerritoryServiceFixture.cs
@@ -0,0 +1,120 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using NorthwindCRUD.Services;
+using NorthwindCRUD.Models.DbModels;
+
+namespace NorthwindCRUD.Tests
+{
+    [TestClass]
+    public class EmployeeTerritoryServiceFixture : BaseFixture
+    {
+        private EmployeeTerritoryService employeeTerritoryService;
+        private EmployeeService employeeService;
+        private TerritoryService territoryService;
+
+        [TestInitialize]
+        public void Initialize()
+        {
+            DataContext context = GetInMemoryDatabaseContext();
+            employeeService = new EmployeeService(context);
+            territoryService = new TerritoryService(context);
+            employeeTerritoryService = new EmployeeTerritoryService(context);
+        }
+
+        static T GetRandomElement<T>(T[] array)
+        {
+            if (array == null || array.Length == 0)
+            {
+                throw new ArgumentException("The array cannot be null or empty.");
+            }
+
+            Random random = new Random();
+            int randomIndex = random.Next(array.Length);
+            return array[randomIndex];
+        }
+
+        [TestMethod]
+        public void ShouldAddTerritoryToEmployee()
+        {
+            var employeeId = GetRandomElement(employeeService.GetAll()).EmployeeId;
+            var territoryId = GetRandomElement(territoryService.GetAll()).TerritoryId;
+
+            var employeeTerritory = new EmployeeTerritoryDb
+            {
+                EmployeeId = employeeId,
+                TerritoryId = territoryId,
+            };
+
+            employeeTerritoryService.AddTerritoryToEmployee(employeeTerritory);
+
+            var territories = employeeTerritoryService.GetTeritoriesByEmployeeId(employeeId);
+            Assert.IsNotNull(territories);
+            Assert.IsTrue(territories.Any(t => t.TerritoryId == territoryId));
+        }
+
+        [TestMethod]
+        public void ShouldReturnTerritoriesForEmployee()
+        {
+            var employeeId = GetRandomElement(employeeService.GetAll()).EmployeeId;
+            var territoryId1 = GetRandomElement(territoryService.GetAll()).TerritoryId;
+            var territoryId2 = GetRandomElement(territoryService.GetAll()).TerritoryId;
+            
+            var initialTerritoryCount = employeeTerritoryService.GetTeritoriesByEmployeeId(employeeId).Count();
+
+            var employeeTerritory = new EmployeeTerritoryDb
+            {
+                EmployeeId = employeeId,
+                TerritoryId = territoryId1,
+            };
+
+            employeeTerritoryService.AddTerritoryToEmployee(employeeTerritory);
+            
+            employeeTerritory = new EmployeeTerritoryDb
+            {
+                EmployeeId = employeeId,
+                TerritoryId = territoryId2,
+            };
+
+            employeeTerritoryService.AddTerritoryToEmployee(employeeTerritory);
+            
+            var territories = employeeTerritoryService.GetTeritoriesByEmployeeId(employeeId);
+
+            Assert.IsNotNull(territories);
+            Assert.AreEqual(initialTerritoryCount + 2, territories.Count());
+            Assert.IsTrue(territories.Any(t => t.TerritoryId == territoryId1));
+            Assert.IsTrue(territories.Any(t => t.TerritoryId == territoryId2));
+        }
+
+        [TestMethod]
+        public void ShouldReturnEmployeesForTerritory()
+        {
+            var employeeId1 = GetRandomElement(employeeService.GetAll()).EmployeeId;
+            var employeeId2= GetRandomElement(employeeService.GetAll()).EmployeeId;
+            var territoryId = GetRandomElement(territoryService.GetAll()).TerritoryId;
+
+            var initialEmployeeCount = employeeTerritoryService.GetEmployeesByTerritoryId(territoryId).Count();
+
+            var employeeTerritory = new EmployeeTerritoryDb
+            {
+                EmployeeId = employeeId1,
+                TerritoryId = territoryId,
+            };
+
+            employeeTerritoryService.AddTerritoryToEmployee(employeeTerritory);
+
+            employeeTerritory = new EmployeeTerritoryDb
+            {
+                EmployeeId = employeeId2,
+                TerritoryId = territoryId,
+            };
+
+            employeeTerritoryService.AddTerritoryToEmployee(employeeTerritory);
+
+            var employees = employeeTerritoryService.GetEmployeesByTerritoryId(territoryId);
+
+            Assert.IsNotNull(employees);
+            Assert.AreEqual(initialEmployeeCount + 2, employees.Count());
+            Assert.IsTrue(employees.Any(e => e.EmployeeId == employeeId1));
+            Assert.IsTrue(employees.Any(e => e.EmployeeId == employeeId2));
+        }
+    }
+}
\ No newline at end of file
diff --git a/NorthwindCRUD.Tests/NorthwindCRUD.Tests.csproj b/NorthwindCRUD.Tests/NorthwindCRUD.Tests.csproj
new file mode 100644
index 0000000..9e0ec45
--- /dev/null
+++ b/NorthwindCRUD.Tests/NorthwindCRUD.Tests.csproj
@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
+    <PackageReference Include="MSTest.TestAdapter" Version="2.2.8" />
+    <PackageReference Include="MSTest.TestFramework" Version="2.2.8" />
+    <PackageReference Include="coverlet.collector" Version="3.1.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\NorthwindCRUD\NorthwindCRUD.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/NorthwindCRUD.sln b/NorthwindCRUD.sln
index 365eb8b..82f9b68 100644
--- a/NorthwindCRUD.sln
+++ b/NorthwindCRUD.sln
@@ -3,7 +3,14 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.2.32526.322
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NorthwindCRUD", "NorthwindCRUD\NorthwindCRUD.csproj", "{43E42C18-0E59-4754-ADF1-25D90114F7E8}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NorthwindCRUD", "NorthwindCRUD\NorthwindCRUD.csproj", "{43E42C18-0E59-4754-ADF1-25D90114F7E8}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NorthwindCRUD.Tests", "NorthwindCRUD.Tests\NorthwindCRUD.Tests.csproj", "{F2C392E4-219B-41F3-8010-10E69EBF434D}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Github Workflows", "Github Workflows", "{816E41A3-F9E9-4244-88C7-930196599CFF}"
+	ProjectSection(SolutionItems) = preProject
+		.github\workflows\build-test-ci.yml = .github\workflows\build-test-ci.yml
+	EndProjectSection
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -15,6 +22,10 @@ Global
 		{43E42C18-0E59-4754-ADF1-25D90114F7E8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{43E42C18-0E59-4754-ADF1-25D90114F7E8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{43E42C18-0E59-4754-ADF1-25D90114F7E8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F2C392E4-219B-41F3-8010-10E69EBF434D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F2C392E4-219B-41F3-8010-10E69EBF434D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F2C392E4-219B-41F3-8010-10E69EBF434D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F2C392E4-219B-41F3-8010-10E69EBF434D}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/NorthwindCRUD/Services/CategoryService.cs b/NorthwindCRUD/Services/CategoryService.cs
index 9a5b406..05056c1 100644
--- a/NorthwindCRUD/Services/CategoryService.cs
+++ b/NorthwindCRUD/Services/CategoryService.cs
@@ -1,18 +1,15 @@
 namespace NorthwindCRUD.Services
 {
-    using AutoMapper;
     using NorthwindCRUD.Helpers;
     using NorthwindCRUD.Models.DbModels;
 
     public class CategoryService
     {
 
-        private readonly IMapper mapper;
         private readonly DataContext dataContext;
 
-        public CategoryService(IMapper mapper, DataContext dataContext)
+        public CategoryService(DataContext dataContext)
         {
-            this.mapper = mapper;
             this.dataContext = dataContext;
         }
 
diff --git a/NorthwindCRUD/Services/EmployeeTerritoryService.cs b/NorthwindCRUD/Services/EmployeeTerritoryService.cs
index df4f47a..b7f3fae 100644
--- a/NorthwindCRUD/Services/EmployeeTerritoryService.cs
+++ b/NorthwindCRUD/Services/EmployeeTerritoryService.cs
@@ -1,20 +1,15 @@
-namespace NorthwindCRUD.Services
-{
-    using AutoMapper;
-    using Microsoft.EntityFrameworkCore;
-    using NorthwindCRUD.Constants;
-    using NorthwindCRUD.Models.Contracts;
-    using NorthwindCRUD.Models.DbModels;
-
+using Microsoft.EntityFrameworkCore;
+using NorthwindCRUD.Constants;
+using NorthwindCRUD.Models.DbModels;
 
+namespace NorthwindCRUD.Services
+{
     public class EmployeeTerritoryService
     {
-        private readonly IMapper mapper;
         private readonly DataContext dataContext;
 
-        public EmployeeTerritoryService(IMapper mapper, DataContext dataContext)
+        public EmployeeTerritoryService(DataContext dataContext)
         {
-            this.mapper = mapper;
             this.dataContext = dataContext;
         }
 
diff --git a/NorthwindCRUD/Services/TerritoryService.cs b/NorthwindCRUD/Services/TerritoryService.cs
index a2485fc..6e56698 100644
--- a/NorthwindCRUD/Services/TerritoryService.cs
+++ b/NorthwindCRUD/Services/TerritoryService.cs
@@ -1,21 +1,16 @@
-namespace NorthwindCRUD.Services
-{
-    using AutoMapper;
-    using Microsoft.EntityFrameworkCore;
-    using NorthwindCRUD.Constants;
-    using NorthwindCRUD.Helpers;
-    using NorthwindCRUD.Models.DbModels;
-    using NorthwindCRUD.Models.Dtos;
+using NorthwindCRUD.Constants;
+using NorthwindCRUD.Helpers;
+using NorthwindCRUD.Models.DbModels;
 
+namespace NorthwindCRUD.Services
+{
     public class TerritoryService
     {
 
-        private readonly IMapper mapper;
         private readonly DataContext dataContext;
 
-        public TerritoryService(IMapper mapper, DataContext dataContext)
+        public TerritoryService(DataContext dataContext)
         {
-            this.mapper = mapper;
             this.dataContext = dataContext;
         }