How have I only just learned of Hyrum’s Law:
With a sufficient number of users of an API, it does not matter what you promise in the contract: all observable behaviors of your system will be depended on by somebody.
To wit: We had an internal API between two components. At one point, as part of a perf optimization, the ordering of the data changed. Well, the other component was relying on that ordering. Oops!
“There’s no way I’m that much more fit,” I thought to myself as Zwift indicated an increase in grade while I seemed to feel nothing. Restart trainer. Reconnect. Start again. “Oh. Oh no…”