Tahnik Services performs the sunnah tahnik for newborns in Singapore. Families come through word of mouth, and the schedule is everything: behind every booking is a family waiting with a newborn, so a missed handoff is never just a bug.
I run the operation systems: booking intake, rostering, reminders, and records, with phone validation handled properly instead of by eye. The tooling is deliberately small and a bit boring. That's on purpose.
This one taught me the most. Small systems, looked after honestly, have outperformed every fancy dashboard I've been tempted to build.