What it is
Gym booking for KEVII Hall at NUS. The whole hall uses it. It replaced the paper sheet. Residents book a slot and check in/out. I handed it to juniors later, and it's still running.
Demerit points
If you book and don't show, or you skip check-in/out, or you walk in without a booking, you get points. No one has to sit there and mark people by hand. That's the main reason people actually book.
Stack
React, Next.js, MongoDB. There's an admin view for bookings, attendance, and points.