Double booking: a transaction plus a partial UNIQUE index
How booking-slots protects against two clients booking the same time at once, and how that protection is tested.
Notes
Short technical notes
I walk through decisions from my projects: what was chosen, why, and what it does not guarantee.
Lease and fencing: how a queue neither loses a job nor lets a zombie finish it twice
A worker can crash, stall, or wake up after its job was taken by someone else. How the lease and the lease token in job-queue deal with that on SQLite.
p95 in an uptime monitor: the nearest-rank method and what it does not hide
How uptime-monitor computes p50/p95 latency and uptime, why the nearest-rank method was chosen, and where those numbers can mislead.
WebSocket on the standard library: what really happens under new WebSocket()
Why realtime-rooms has its own RFC 6455 layer, which protocol violations it checks, and why a library is still the better choice for production.