Why API design matters more than it looks

This is cheap to get right at the start and expensive to retrofit. API design is easy to treat as a detail, and that is exactly why it is worth a few minutes of attention.

Code gets read far more often than it gets written, and usually by someone with less context than the author had. If it only works because one person remembers to do something, it does not work yet.

The reason this keeps coming up

Consistent naming saves every future integrator hours. Small and consistent beats large and occasional here. The failure mode is not doing it wrong, it is doing it once and assuming it stays done.

Version the API before anyone else depends on it. None of that requires a large budget, only a decision and someone to own it. The failure mode is not doing it wrong, it is doing it once and assuming it stays done.

The mistakes we see most

Errors should be as well designed as successes. This is the sort of thing that compounds, quietly, in both directions. Most teams find the first pass takes an afternoon and the maintenance takes minutes a month.

What this looks like day to day

The question is rarely whether something can be built, but what it costs to keep running afterwards. Three things worth confirming about API design before you move on:

• Someone can say what the current setup is without going to look
• Errors should be as well designed as successes — and you know whether that is true here
• There is a way to tell whether the last change to this helped

None of this needs a rewrite. Most of it is a morning's work once someone decides to do it.