Performance

Claude Code is billed by tokens, and its token use is driven less by how much you type than by how much context it carries: every request sends the conversation…

In a small repository, Claude Code's defaults work: one CLAUDE.md, launch from the root, let it search. In a monorepo with dozens of packages, the same defaults…

PostgreSQL never overwrites a row in place. An UPDATE writes a new version of the row and marks the old one as replaced; a DELETE only marks the row. That desig…

Every request Claude Code sends to the model carries the whole session so far: the system prompt, your CLAUDE.md files, every message, every file Claude read, a…

A product manager says PAY-204: next Friday's campaign may double checkout traffic for three hours. The beginner mistake is asking, "How many servers do we need…

A dashboard can look “fast” while users still wait, and a load test can report huge requests-per-second while p99 checkout times explode. Latency is how long on…

You press Enter on https://shop.example/products/42. A moment later, a product page appears. That small action crosses naming, transport security, HTTP, edge in…

Checkout slows while product pages remain healthy. CPU is moderate, but the orders table shows rising lock waits and writes queue behind one hot index. Adding a…

A product page is easy to cache until a price changes: the CDN still has the old response, one app instance has an older in-process value, and Redis has already…

A product page's cache key expires at 2:00:00pm. In the same instant, 5,000 concurrent requests check the cache, all get a miss, and all 5,000 independently que…