Tag
3 posts
1 post
Designing the push-notification service: idempotency keys as mandatory input, durable in-app records before OS push, fail-open preferences, receipt reconciliation, and WebSocket auth via subprotocol.
1 post
Third-party webhooks expire, get orphaned by restarts, and miss events. A reconcile-loop design that converges desired vs. live state, plus deduplication by join URL and latches that remember deliberate exits.
1 post
Two small algorithms that make a notification service boring in the best way: cursor pagination that cannot skip rows, and exactly-once-flavored dispatch built on a single SQL statement.