+1000 to this. The "API" that developers see is the tip of the iceberg for what actually goes into publicly exposing a service to developers. Yes there's quite

+1000 to this. The "API" that developers see is the tip of the iceberg for what actually goes into publicly exposing a service to developers. Yes there's quite a bit of internal maintenance that goes on (as mentioned, lots of things change frequently, though generally people refactoring chunks of code will "upgrade" your code for you, since if they don't they can't submit their changes since you were a good engineer and wrote defensive unit tests to protect your code). Maintaining a public API can also mean having: - Documentation (up to 15 languages) - Sample code/example apps (up to 7 languages) - Support (Stack Overflow, Quora, etc.) - An on-call rotation