ZATS (zakyalwie.sg) connects families with Islamic service providers in Singapore. Bookings used to run on WhatsApp threads. That worked until it didn't: double bookings, missed messages, no record of anything.
I built the booking platform end to end: the service catalogue, availability, confirmations, and error monitoring through Sentry with environment labels sensible enough that real problems surface and noise doesn't.
The number I care about is simple: a parent can book a service in under two minutes on their phone, without calling anyone. Everything else serves that.