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..74c0e0167 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..dc59d8fae
--- /dev/null
+++ b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeManagerTest.java
@@ -0,0 +1,78 @@
+package com.codedifferently.lesson15;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class EmployeeManagerTest {
+
+  EmployeeManager employeeManager;
+  Employee employee;
+  Employee employee2;
+
+  @BeforeEach
+  public void setUp() {
+    employeeManager = new EmployeeManager();
+    employee = new Employee(0, "Zion", "Code Differently", 0);
+  }
+
+  @Test
+  public void testAddEmployee() {
+    employeeManager.addEmployee(employee);
+    assertEquals(1, employeeManager.getEmployeeCount());
+  }
+
+  @Test
+  public void testGetEmployee() {
+    employeeManager.addEmployee(employee);
+    assertEquals(employeeManager.getEmployee(employee.getId()), employee);
+  }
+
+  @Test
+  public void testupdateEmployee() {
+    employeeManager.addEmployee(employee);
+    employee2 = new Employee(0, "Andre", "JP Morgan", 0);
+    employeeManager.updateEmployee(employee2);
+    assertEquals(employeeManager.getEmployee(employee2.getId()), employee2);
+  }
+
+  @Test
+  public void testSetName() {
+    employee.setName("Zion");
+    assertEquals(employee.getName(), "Zion");
+  }
+
+  @Test
+  public void testGetDepartment() {
+    employee.getDepartment();
+    assertEquals(employee.getDepartment(), "Code Differently");
+  }
+
+  @Test
+  public void testSetDepartment() {
+    employee.setDepartment("Code Differently");
+    assertEquals(employee.getDepartment(), "Code Differently");
+  }
+
+  @Test
+  public void testGetDetails() {
+    assertEquals(employee.getDetails(), "Id 0 Name: Zion department Code Differently0.0 salary");
+  }
+
+  @Test
+  public void testRemoveEmployee() {
+    // Setup
+    var id = 0;
+
+    // Execute
+    employeeManager.addEmployee(employee);
+    employeeManager.removeEmployee(id);
+
+    // Assert
+    assertThatThrownBy(() -> employeeManager.getEmployee(id))
+        .isInstanceOf(IllegalArgumentException.class)
+        .hasMessage("Employee does not in collection with id " + id);
+  }
+}
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..56ae75201
--- /dev/null
+++ b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/EmployeeTest.java
@@ -0,0 +1,66 @@
+package com.codedifferently.lesson15;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class EmployeeTest {
+  Employee employee;
+
+  @BeforeEach
+  public void setUp() {
+    employee = new Employee(0, "Zion", "Code Differently", 0);
+  }
+
+  @Test
+  public void testGetId() {
+    employee.getId();
+    assertEquals(employee.getId(), 0);
+  }
+
+  @Test
+  public void testSetId() {
+    employee.setId(1);
+    assertEquals(employee.getId(), 1);
+  }
+
+  @Test
+  public void testGetName() {
+    assertEquals(employee.getName(), "Zion");
+  }
+
+  @Test
+  public void testSetName() {
+    employee.setName("Zion");
+    assertEquals(employee.getName(), "Zion");
+  }
+
+  @Test
+  public void testGetDepartment() {
+    employee.getDepartment();
+    assertEquals(employee.getDepartment(), "Code Differently");
+  }
+
+  @Test
+  public void testSetDepartment() {
+    employee.setDepartment("Code Differently");
+    assertEquals(employee.getDepartment(), "Code Differently");
+  }
+
+  @Test
+  public void testGetDetails() {
+    assertEquals(employee.getDetails(), "Id 0 Name: Zion department Code Differently0.0 salary");
+  }
+
+  @Test
+  public void testGetSalary() {
+    employee.getSalary();
+    assertEquals(employee.getSalary(), 0);
+  }
+
+  @Test
+  public void testSetSalary() {
+    assertEquals(employee.getSalary(), 0);
+  }
+}