Writing
Backend engineering notes.
Notes on reliability, event-driven systems, and the trade-offs I run into while building them. You can also follow the RSS feed.
Tuple visibility in PostgreSQL: debugging with xmin, xmax, and pg_locks
Every row in PostgreSQL carries hidden versioning metadata. This is how to read it, what it means, and how to use it when queries return unexpected results.
SQS is not a broadcast bus: fixing GraphQL subscription fan-out
How competing SQS consumers can drop the notification a GraphQL client is waiting for, and the direct-SQS design I used instead.
Reliable webhook delivery: designing for the failures between systems
Notes from building Webhook Relay: transactional outboxes, at-least-once delivery, idempotency, retries, dead letters, replay, and request signing.