The Refund Agent will not refund until the carrier confirms the return. The Shipping Agent will not create a return label until the refund is approved. Each rule is correct.
A payment commits, the API returns 200, the rack loses power, and after recovery the row does not exist. Before blaming the database, six questions have to be separated.
A timeout is not a failure. Ten real ways idempotency keys break in payment systems — lost gateway responses, two tabs, racing retries, Redis evictions, expired keys, duplicate webhooks — with the fix for each, ten…
You add 24 more workers to fix Kafka lag — and they all sit idle. Meanwhile one huge message is stuck at the front of a partition, and nothing behind it moves.
Not a "what is Lambda" post. A deep dive into how Lambda actually works: Firecracker microVMs and the Worker/placement fleet, how invocations get routed on the warm vs cold path, and what the INIT phase really does (and…
“We sold 3 tickets but only had 1.” The code is inside a transaction, looks right, works a hundred times locally, and only breaks in production under load.
I'm Amit Verma, a software engineer working on distributed systems — Kafka pipelines, WebSocket infrastructure, and the databases underneath them.
This publication exists because most content shows the clean answer. Here you get the real problem: the production failure, the approaches that didn't work, the technical decision, and the lesson that stuck.