May 23 · 5 min read · How to Implement Idempotency in a NestJS + PostgreSQL Stack If you've ever built a payment flow or an order creation endpoint, you've probably faced this scenario: the user clicks "Submit", the networ
Join discussion
May 13 · 14 min read · In Part 2, the TCP handshake cost was a fundamental transaction cost for every connection. In Part 3, HTTP underwent three structural shifts to overcome that specific cost. In Part 4, load balancers d
Join discussion
Feb 1 · 6 min read · If cron has a single moral lesson, it’s this: time does not guarantee uniqueness. Jobs run twice. Or zero times. Or half a time. Or later than expected. Cron does not promise exactly once execution, and every system that assumes it does eventually pa...
Join discussion
Jan 26 · 9 min read · When you read about idempotency the first time, it sounds reasonably precise and simple. The definition is short: performing the same operation multiple times should have the same effect as performing it once. On paper, it feels like a solid guarante...
Join discussion
Jan 17 · 7 min read · Cron failures are rarely dramatic. There’s no stack trace on your screen, no angry user clicking refresh. Instead, something subtle doesn’t happen. A report isn’t generated. A cleanup never runs. A notification arrives late—or twice. And when you inv...
Join discussion
Jan 11 · 3 min read · Today, I was working on an admin panel feature. Simple task.One button.One API. 👉 “Create Policy” I clicked the button. Policy created ✅Clicked again (by mistake)…Another policy created ❌Clicked again (slow network)…Boom — three duplicate records. N...
Join discussionJan 5 · 10 min read · Assume you are making a very simple login system. A user sends a request with a username and password. Let us list down what all needs to be present in the system. If the credentials are valid, a session should be created. All the authorized action...
Join discussion
Nov 20, 2025 · 13 min read · Introduction: The Interview Paradox Picture this: you're sitting in an interview, and the interviewer asks, "What HTTP status codes do you know?" or "What's the difference between GET and POST?" Almost every candidate confidently rattles off the same...
Join discussion
Nov 3, 2025 · 20 min read · In simple terms, Idempotency in HTTP requests is “doing the same operation multiple times has the same effect as doing it once”. For operations that create side effects, e.g. POST requests, idempotency keys let the server detect duplicate attempts an...
Join discussion
