Engineering notes
How BuildAPI works underneath, what we got wrong, and what we changed. Written by the people who broke it.
Tests that fail when you break them
A passing test proves nothing until you have watched it fail for the right reason.
What a fresh install should look like
Correct on arrival, not correct after something repairs it.
A quote and a charge must be one number
The moment those are two implementations, they diverge — and the customer finds out at the card.
The cron that nobody scheduled
Background work that only runs when someone visits is not background work.
Pricing in one currency, charging in another
We quote in dollars and charge in naira. Almost every bug we shipped this year lived in that gap.
Designing a refusal message
Most systems tell the user what happened. Good ones tell them what to do.
Proration done properly
Charging full price for a mid-cycle upgrade forfeits what the customer already paid. People notice once and never forgive it.
The outage rule: what should happen when we are down
A licensing check that takes your site down during our outage is worse than no licensing check.