Back-end systems are a particular strength of mine and they offer a great place for efficient and flexible design.
Even the snappiest user experience can be brought down by an unresponsive or unreliable back-end.
In my experience, the service layer is where the essence of a system lives. Whether it’s real-world business logic playing out or a quiet background worker keeping everything in check, a back-end that will stand the test of time demands systems thinking and consideration of extensibility, scalability and security.