Business-critical code is typically complex because it’s required to handle multiple use cases for many different customers. The complexity grows over time as new use cases are discovered and new customers are supported. However, business-critical code doesn’t necessarily equate to state-of-the-art code. Surprisingly, the most profitable code is sometimes rather outdated and boring. The most important part is that the code works, is reliable, gets the job done, and is in the hands of the customer.