Tournament logistics, automated end to end
Diamond Connect runs youth baseball tournaments end to end: teams register and pay, brackets and schedules generate themselves, and results come back from the field to everyone following the tournament.
It was my first production system, and the one that taught me that the scheduling constraint nobody mentions in the requirements is the one that breaks your weekend.
Fields, umpires, rest windows between games and team availability all constrain each other. The generator assigns slots against those constraints and reports genuine conflicts instead of silently producing an impossible schedule.
A team is only registered once Stripe confirms via webhook, not when the client thinks checkout succeeded. Idempotent webhook handling means a retried event never creates a duplicate registration.
Scorekeepers work on stadium wifi. Updates are queued client-side and reconciled when the connection returns, so a dropped signal delays the feed rather than losing an inning.