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..3db358696 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 +45,15 @@ public double getSalary() {
   public void setSalary(double salary) {
     this.salary = salary;
   }
+
+  public String getDetails() {
+    return "ID: "
+        + getId()
+        + ", Name: "
+        + getName()
+        + ", Department: "
+        + getDepartment()
+        + ", Salary: "
+        + getSalary();
+  }
 }
diff --git a/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/Lesson15Test.java b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/Lesson15Test.java
index cd6ef511e..67843ec29 100644
--- a/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/Lesson15Test.java
+++ b/lesson_15/tdd/tdd_app/src/test/java/com/codedifferently/lesson15/Lesson15Test.java
@@ -1,6 +1,7 @@
 package com.codedifferently.lesson15;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import org.junit.jupiter.api.Test;
 
@@ -16,4 +17,65 @@ public void testGetGreeting() {
     // Act
     Lesson15.main(null);
   }
+
+  @Test
+  public void employeeManagerAddEmployee() {
+    Employee employee = new Employee(0, null, null, 0);
+    EmployeeManager manager = new EmployeeManager();
+    manager.addEmployee(employee);
+
+    assertEquals(employee, manager.getEmployee(0));
+  }
+
+  @Test
+  public void employeeManagerRemoveEmployee() {
+    Employee employee = new Employee(0, null, null, 0);
+    EmployeeManager manager = new EmployeeManager();
+    manager.addEmployee(employee);
+
+    manager.removeEmployee(0);
+
+    assertEquals(0, manager.getEmployeeCount());
+  }
+
+  @Test
+  public void employeeManagerUpdateEmployee() {
+    Employee employee = new Employee(0, null, null, 0);
+    Employee employee2 = new Employee(0, "test", "dept", 0);
+    EmployeeManager manager = new EmployeeManager();
+    manager.addEmployee(employee);
+
+    manager.updateEmployee(employee2);
+
+    assertEquals(
+        "ID: 0, Name: test, Department: dept, Salary: 0.0", manager.getEmployee(0).getDetails());
+  }
+
+  @Test
+  public void getEmployeeDepartment() {
+    Employee employee = new Employee(0, null, "fryCook", 0);
+
+    assertEquals("fryCook", employee.getDepartment());
+  }
+
+  @Test
+  public void getEmployeeSalary() {
+    Employee employee = new Employee(0, null, "fryCook", 999_999);
+
+    assertEquals(999_999, employee.getSalary());
+  }
+
+  @Test
+  public void getEmployeeName() {
+    Employee employee = new Employee(0, "James Bartholomew the III", "fryCook", 999_999);
+    assertEquals("James Bartholomew the III", employee.getName());
+  }
+
+  @Test
+  public void getEmployeeDetails() {
+    Employee employee = new Employee(0, "James Bartholomew the III", "fryCook", 999_999);
+    assertEquals(
+        "ID: 0, Name: James Bartholomew the III, Department: fryCook, Salary: 999999.0",
+        employee.getDetails());
+  }
 }