/\
       /E2E\        Few, slow, critical paths
      /------\
     / Integ- \     Some, key integrations
    /--ration--\
   /    Unit    \   Many, fast, isolated
  /--------------\

[Fact]
public void Method_Scenario_Expected()
{
    // Arrange - Set up test data
    var input = CreateInput();
    
    // Act - Execute the code
    var result = Process(input);
    
    // Assert - Verify outcome
    Assert.Equal(expected, result);
}