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..9b3628e39 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 + " " + name + " " + department + " " + salary + ".";
+  }
 }
diff --git a/lesson_15/tdd/tdd_app/src/test/java/EmployeeManagerTest.java b/lesson_15/tdd/tdd_app/src/test/java/EmployeeManagerTest.java
new file mode 100644
index 000000000..4fb29b324
--- /dev/null
+++ b/lesson_15/tdd/tdd_app/src/test/java/EmployeeManagerTest.java
@@ -0,0 +1,63 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import com.codedifferently.lesson15.Employee;
+import com.codedifferently.lesson15.EmployeeManager;
+
+public class EmployeeManagerTest {
+  Employee employee;
+  EmployeeManager employeeManager;
+  Employee employeeNew;
+
+  @BeforeEach
+  void setUp() {
+    employee = new Employee(15, "Pablo", "Emperor", 100);
+    employeeManager = new EmployeeManager();
+  }
+
+  @Test
+  void testAddEmployee() {
+    employeeManager.addEmployee(employee);
+
+    assertEquals(1, employeeManager.getEmployeeCount());
+  }
+
+  @Test
+  void testGetEmployee() {
+    employeeManager.addEmployee(employee);
+
+    assertEquals(employee, employeeManager.getEmployee(employee.getId()));
+  }
+
+  @Test
+  void testUpdateEmployee() {
+    employeeNew = new Employee(15, "Paul", "President", 200);
+
+    employeeManager.addEmployee(employee);
+
+    employeeManager.updateEmployee(employeeNew);
+
+    assertEquals(employeeManager.getEmployee(employeeNew.getId()), employeeNew);
+  }
+
+  @Test
+  void testRemoveEmployee() {
+    employeeManager.addEmployee(employee);
+
+    employeeManager.removeEmployee(employee.getId());
+
+    assertEquals(0, employeeManager.getEmployeeCount());
+  }
+
+  @Test
+  void testGetEmployeeCount() {
+    employeeNew = new Employee(16, "Paul", "President", 200);
+
+    employeeManager.addEmployee(employee);
+
+    employeeManager.addEmployee(employeeNew);
+
+    assertEquals(2, employeeManager.getEmployeeCount());
+  }
+}
diff --git a/lesson_15/tdd/tdd_app/src/test/java/EmployeeTest.java b/lesson_15/tdd/tdd_app/src/test/java/EmployeeTest.java
new file mode 100644
index 000000000..fec568969
--- /dev/null
+++ b/lesson_15/tdd/tdd_app/src/test/java/EmployeeTest.java
@@ -0,0 +1,70 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.codedifferently.lesson15.Employee;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class EmployeeTest {
+
+  Employee employee;
+
+  @BeforeEach
+  void setUp() {
+    employee = new Employee(15, "Pablo", "Emperor", 100.0);
+  }
+
+  @Test
+  void testgetId() {
+    assertEquals(15, employee.getId());
+  }
+
+  @Test
+  void testsetId() {
+
+    employee.setId(12);
+
+    assertEquals(12, employee.getId());
+  }
+
+  @Test
+  void testgetName() {
+    assertEquals("Pablo", employee.getName());
+  }
+
+  @Test
+  void testsetName() {
+    employee.setName("John");
+
+    assertEquals("John", employee.getName());
+  }
+
+  @Test
+  void testgetDepartment() {
+    assertEquals("Emperor", employee.getDepartment());
+  }
+
+  @Test
+  void testsetDepartment() {
+    employee.setDepartment("Monk");
+
+    assertEquals("Monk", employee.getDepartment());
+  }
+
+  @Test
+  void testgetSalary() {
+    assertEquals(100.0, employee.getSalary());
+  }
+
+  @Test
+  void testsetSalary() {
+    employee.setSalary(1000000.0);
+
+    assertEquals(1000000.0, employee.getSalary());
+  }
+
+  @Test
+  void getDetails() {
+    String expectedDetails = "15 Pablo Emperor 100.0.";
+    assertEquals(expectedDetails, employee.getDetails());
+  }
+}