diff --git a/lesson_15/tdd/tdd_app/src/main/java/com/codedifferently/lesson15/Employee.java b/lesson_15/tdd/tdd_app/src/main/java/com/codedifferently/lesson15/Employee.java
index 49aaabbd7..e5282c675 100644
--- a/lesson_15/tdd/tdd_app/src/main/java/com/codedifferently/lesson15/Employee.java
+++ b/lesson_15/tdd/tdd_app/src/main/java/com/codedifferently/lesson15/Employee.java
@@ -45,4 +45,8 @@ public double getSalary() {
   public void setSalary(double salary) {
     this.salary = salary;
   }
+
+  public String getDetails() {
+    return "id: " + id + "name: " + name + "department: " + department + "salary: " + salary;
+  }
 }
diff --git a/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeManagerTest.java b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeManagerTest.java
new file mode 100644
index 000000000..89e8bdcec
--- /dev/null
+++ b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeManagerTest.java
@@ -0,0 +1,76 @@
+package com.codedifferently.lesson15;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class EmployeeManagerTest {
+
+  EmployeeManager employeeManager;
+  List<Employee> employees;
+
+  // Set up
+  @BeforeEach
+  void setUp() {
+    employeeManager = new EmployeeManager();
+    Employee employee = new Employee(0, "Nitsua", "Sales", 65000.00);
+    employeeManager.addEmployee(employee);
+    employees = new ArrayList();
+    employees.add(employee);
+  }
+
+  @Test
+  public void testAddEmployee() {
+    // Arrange
+    Employee employee1 = new Employee(1, "Penny", "Sales", 65000.00);
+    // Act & Assert
+    employeeManager.addEmployee(employee1);
+    assertEquals(employee1, employeeManager.getEmployee(1));
+  }
+
+  @Test
+  public void testGetEmployee() {
+    // Arrange
+    Employee employee = new Employee(0, "Nitsua", "Sales", 65000.00);
+    Employee expectedEmployee = employeeManager.getEmployee(employee.getId());
+    // Act
+    Employee actualEmployee = employeeManager.getEmployee(0);
+    // Assert
+    assertEquals(expectedEmployee, actualEmployee);
+  }
+
+  @Test
+  public void testUpdateEmployee() {
+    // Arrange
+    Employee expectedEmployeeUpdate = new Employee(0, "Nitsua", "Tech", 100000.00);
+    // Act
+    employeeManager.updateEmployee(expectedEmployeeUpdate);
+    // Act
+    assertEquals(expectedEmployeeUpdate, employeeManager.getEmployee(0));
+  }
+
+  @Test
+  public void testRemoveEmployee() {
+    // Arange
+    Employee employee = new Employee(0, "Nitsua", "Sales", 65000.00);
+    employeeManager.addEmployee(employee);
+    // Act
+    employeeManager.removeEmployee(0);
+    // Assert
+    assertThatThrownBy(() -> employeeManager.removeEmployee(0))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Employee does not in collection with id " + employee.getId());
+  }
+
+  @Test
+  public void testGetEmployeeCount() {
+    // Act
+    int actualEmployeeCount = employeeManager.getEmployeeCount();
+    // Assert(recieved help from Vicente on employees array)
+    assertEquals(employees.size(), actualEmployeeCount);
+  }
+}
diff --git a/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeTest.java b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeTest.java
new file mode 100644
index 000000000..3361a5f57
--- /dev/null
+++ b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeTest.java
@@ -0,0 +1,116 @@
+package com.codedifferently.lesson15;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class EmployeeTest {
+
+  Employee employee;
+
+  // Set up
+  @BeforeEach
+  void setUp() {
+    employee = new Employee(19, "Chigazo", "Finance", 50000.00);
+  }
+
+  @Test
+  // Method being tested
+  public void testGetId() {
+    // Execersise
+    int actualId = employee.getId();
+
+    int expectedId = 19;
+    // Assert(Checking the value)
+    assertEquals(expectedId, actualId);
+  }
+
+  @Test
+  public void testSetID() {
+    // Arrange
+    int expectedSetId = 91;
+    // Act
+    employee.setId(expectedSetId);
+    // Assert
+    assertEquals(expectedSetId, employee.getId());
+  }
+
+  @Test
+  public void testGetName() {
+    // Arrange
+    String expectedName = "Chigazo";
+    // Act
+    String actualName = employee.getName();
+    // Assert
+    assertEquals(expectedName, actualName);
+  }
+
+  @Test
+  public void testSetName() {
+    // Arrange
+    String expectedSetName = "Austin";
+    // Act
+    employee.setName(expectedSetName);
+    // Assert
+    assertEquals(expectedSetName, employee.getName());
+  }
+
+  @Test
+  public void testGetDepartment() {
+    // Arrange
+    String actualDepartment = "Finance";
+    // Act
+    String expectedDepartment = employee.getDepartment();
+    // Assert
+    assertEquals(expectedDepartment, actualDepartment);
+  }
+
+  @Test
+  public void testSetDepartment() {
+    // Arrange
+    String expectedSetDepartment = "Tech";
+    // Act
+    employee.setDepartment(expectedSetDepartment);
+    // Assert
+    assertEquals(expectedSetDepartment, employee.getDepartment());
+  }
+
+  @Test
+  public void testGetSalary() {
+    // Arrange
+    double actualSalary = 50000.00;
+    // Act
+    double expectedSalary = employee.getSalary();
+    // Assert
+    assertEquals(expectedSalary, actualSalary);
+  }
+
+  @Test
+  public void testSetSalary() {
+    // Arrange
+    double expectedSetSalary = 100000.00;
+    // Act
+    employee.setSalary(expectedSetSalary);
+    // Assert
+    assertEquals(expectedSetSalary, employee.getSalary());
+  }
+
+  @Test
+  public void testGetDetails() {
+    // Arrange
+    String actualDetails =
+        "id: "
+            + employee.getId()
+            + "name: "
+            + employee.getName()
+            + "department: "
+            + employee.getDepartment()
+            + "salary: "
+            + employee.getSalary();
+    // Act
+    String expectedDetails = employee.getDetails();
+    // Assert
+    assertEquals(expectedDetails, actualDetails);
+  }
+}