Arun Arivanandam builds resilient full-stack web applications with MongoDB, Express, React and Node. Selected work, writing on backend architecture, and how to get in touch.https://arunarivanandam.dev/en-inhttps://arunarivanandam.dev/blog/usestate/https://arunarivanandam.dev/blog/usestate/Learn react useState hook from first principles. Use states with confidence.Thu, 17 Sep 2026 00:00:00 GMTreactjavascriptarchitecturehttps://arunarivanandam.dev/blog/what-change-streams-cost-you/https://arunarivanandam.dev/blog/what-change-streams-cost-you/Change streams removed a polling loop and a whole class of duplicate-payout bugs. They also introduced three failure modes I had not budgeted for.Wed, 19 Aug 2026 00:00:00 GMTmongodbnodearchitecturehttps://arunarivanandam.dev/blog/business-logic-in-middleware/https://arunarivanandam.dev/blog/business-logic-in-middleware/Middleware that mutates the request object reads like dependency injection and behaves like a global variable. Here is the refactor that finally stuck.Thu, 04 Jun 2026 00:00:00 GMTexpressnodearchitecturehttps://arunarivanandam.dev/blog/react-data-layer-bad-network/https://arunarivanandam.dev/blog/react-data-layer-bad-network/Notes from building an offline-first pharmacy app for shops on 2G, where the connection is not an edge case but the normal operating condition.Sat, 11 Apr 2026 00:00:00 GMTreactofflinearchitecture