Devmayor technical writingTechnical essays about backend systems and production engineering.https://devmayor.dev/Rebuilding the whole request end to endhttps://devmayor.dev/blog/rebuilding-request-end-to-end/https://devmayor.dev/blog/rebuilding-request-end-to-end/We put the full request back together, from the browser and network to Node, PostgreSQL, payments, queues, and the final response.Tue, 29 Sep 2026 00:00:00 GMTWhat changes when 10,000 users place orders at once?https://devmayor.dev/blog/ten-thousand-users-place-orders/https://devmayor.dev/blog/ten-thousand-users-place-orders/A traffic spike fills queues, exhausts connection pools, hits hot rows, and turns careless retries into even more traffic.Tue, 29 Sep 2026 00:00:00 GMTThe request took 1.8 seconds. Where did the time go?https://devmayor.dev/blog/where-request-time-went/https://devmayor.dev/blog/where-request-time-went/The request took 1.8 seconds. Traces, metrics, and logs help us see how much time each part of the system used.Tue, 29 Sep 2026 00:00:00 GMTThe payment provider takes four seconds. Should our request wait?https://devmayor.dev/blog/payment-provider-four-seconds/https://devmayor.dev/blog/payment-provider-four-seconds/A four-second payment call forces us to choose: keep the request open, or return a pending order and finish the work in the background.Tue, 29 Sep 2026 00:00:00 GMTTwo people try to buy the last itemhttps://devmayor.dev/blog/two-buyers-last-item/https://devmayor.dev/blog/two-buyers-last-item/Two buyers see one item in stock. We need one safe place to decide who gets it and stop the other order.Tue, 29 Sep 2026 00:00:00 GMTHow did PostgreSQL find one row among millions without scanning everything?https://devmayor.dev/blog/postgresql-find-row-among-millions/https://devmayor.dev/blog/postgresql-find-row-among-millions/A B-tree index helps PostgreSQL narrow millions of rows to a few candidates, as long as the index actually matches the query.Tue, 29 Sep 2026 00:00:00 GMTThe API needs your order. What happens inside PostgreSQL?https://devmayor.dev/blog/inside-postgresql-order-query/https://devmayor.dev/blog/inside-postgresql-order-query/One line of SQL hides a connection pool, a query plan, memory pages, MVCC rules, storage work, and a result that still has to come back.Tue, 29 Sep 2026 00:00:00 GMTNode is single-threaded. So how is it handling thousands of requests?https://devmayor.dev/blog/node-single-threaded-thousands-requests/https://devmayor.dev/blog/node-single-threaded-thousands-requests/Node handles many requests by keeping the JavaScript thread free while the operating system and supporting workers handle most of the waiting.Tue, 29 Sep 2026 00:00:00 GMTWhat actually happens when Node receives the request?https://devmayor.dev/blog/what-node-does-with-request/https://devmayor.dev/blog/what-node-does-with-request/Your controller is near the end of the path. The operating system, Node's HTTP parser, middleware, and router all see the request first.Tue, 29 Sep 2026 00:00:00 GMTYour request reached us. Which server gets it?https://devmayor.dev/blog/which-server-gets-request/https://devmayor.dev/blog/which-server-gets-request/The public endpoint is the front door. Load balancers, proxies, health checks, and routing rules still have to choose an application server.Tue, 29 Sep 2026 00:00:00 GMTWhy HTTPS needs work before your request even startshttps://devmayor.dev/blog/https-before-request-starts/https://devmayor.dev/blog/https-before-request-starts/Before the browser sends a secure request, it has to verify the server, agree on keys, and work out which connection it can reuse.Tue, 29 Sep 2026 00:00:00 GMTYou clicked Place Order. What happens before my backend sees it?https://devmayor.dev/blog/place-order-before-backend/https://devmayor.dev/blog/place-order-before-backend/Before your backend can process an order, the browser has to find the service, open a connection, secure it, and get through the edge.Tue, 29 Sep 2026 00:00:00 GMT