The Importance of Maintainability in Legacy Code

When you say API, there's kind of two meanings to that term. It's probably more common to use API to refer when you are programmatically working against a service, or a system. You could have an object that literally defines 30 methods right in the same file. That might not be very cohesive. And so to keep that object cohesive, you might move that chunk of five methods somewhere else. But then your code can still maintain cohesion. There is a book by Michael Feathers called Working Effectively with legacy code.