Designing a slot-booking flow people don't fight

A client came to me with a portfolio site that needed a slot booking system. Simple, they said. Then real calendars showed up: double-bookings, timezone confusion, cancellations, and people who expected a confirmation email within seconds.

We designed real-time availability with no double-booking window, an explicit confirmation path, and zero ambiguity about what happens next — plus a clean way to cancel that doesn't punish the visitor.

The lesson I keep learning: . It's in the questions you forgot to ask upfront — what happens when someone books twice, or when the slot they just wanted closed? Answer those and the code is almost boring.the friction is never in the calendar