--- title: "Ahmed Mahsook (@mahsook) | Hashnode" description: "Backend engineering notes from building real systems Go, concurrency, and distributed backends. Read the latest articles by Ahmed Mahsook on Hashnode." url: "https://hashnode.com/@mahsook" --- @mahsook # Ahmed Mahsook @mahsook · Bangalore, India · Joined September 2026 Backend engineering notes from building real systems Go, concurrency, and distributed backends. ### [Building a Financially Correct Wallet and Settlement System in Go](https://ahmedmahsook.hashnode.dev/building-a-financially-correct-wallet-and-settlement-system-in-go?utm_source=hashnode&utm_medium=feed) Learn how I built a reliable Go wallet system using idempotency, PostgreSQL transactions, concurrency control, integer money, and settlement. 8 min read · [ahmedmahsook.hashnode.dev](https://ahmedmahsook.hashnode.dev/building-a-financially-correct-wallet-and-settlement-system-in-go?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/building-a-financially-correct-wallet-and-settlement-system-in-go/6ac38c9a1660a1707daf5671) [Oct 5](https://hashnode.com/posts/building-a-financially-correct-wallet-and-settlement-system-in-go/6ac38c9a1660a1707daf5671) ### [Idempotency in a Go Wallet System: How I Made Sure Money Never Moves Twice](https://ahmedmahsook.hashnode.dev/idempotency-in-a-go-wallet-system-how-i-made-sure-money-never-moves-twice?utm_source=hashnode&utm_medium=feed) How database-level uniqueness constraints in Go prevent duplicate wallet holds, releases, and settlement payouts in a concurrent auction system. 5 min read · [ahmedmahsook.hashnode.dev](https://ahmedmahsook.hashnode.dev/idempotency-in-a-go-wallet-system-how-i-made-sure-money-never-moves-twice?utm_source=hashnode&utm_medium=feed) [Oct 1](https://hashnode.com/posts/idempotency-in-a-go-wallet-system-how-i-made-sure-money-never-moves-twice/6abe0d163adb4db48852366b) ### [Building a Crash-Safe Bid Engine in Go: Heaps, Race Conditions, and Recovery](https://ahmedmahsook.hashnode.dev/building-a-crash-safe-bid-engine-in-go-heaps-race-conditions-and-recovery?utm_source=hashnode&utm_medium=feed) How I built a concurrent bid-matching engine in Go with heaps, fixed a self-deadlock bug, and made it recover from a crash via event replay. 6 min read · [ahmedmahsook.hashnode.dev](https://ahmedmahsook.hashnode.dev/building-a-crash-safe-bid-engine-in-go-heaps-race-conditions-and-recovery?utm_source=hashnode&utm_medium=feed) [Sep 29](https://hashnode.com/posts/building-a-crash-safe-bid-engine-in-go-heaps-race-conditions-and-recovery/6abb5868f2b1c1b8d293d1bd)