Deepak Kumar
Full stack engineer working on performance, data modelling and integrations for high traffic products.
Projects
All · 6Recent writing
- Load-Testing a URL Shortener Pushing the linkpulse redirect path with k6 until something gave. A fixed VU test measures concurrency, not throughput, and at 3,000 requests a second one Node process ran out of CPU while Redis and Postgres sat at about 25%. Part 2 · Medium (opens in a new tab)
- Building a URL Shortener: Six Design Decisions and the Alternatives I Rejected Six decisions behind a URL shortener that runs in public, each with the alternative I rejected: a 302 rather than a 301, caching misses as well as hits, a sliding window rate limiter in Lua, and refresh tokens with reuse detection. Part 1 · Medium (opens in a new tab)
- Testing WP-CLI Commands with PHPUnit and Behat What to prove about a WP-CLI command before it runs unattended against production. PHPUnit for the logic, Behat against the real wp binary, and the places WP-CLI resists unit testing. Medium (opens in a new tab)
- I Built a Twitter-Style Feed to Find Out What Fan-Out Actually Costs Push and pull feeds built over the same data and measured. Fan-out costs about 12 microseconds per follower, a timeline entry about 80 bytes in Redis, and the read advantage was far smaller than expected. Part 2 · Medium (opens in a new tab)
- Celebrities vs. The Rest of Us: Designing a Twitter-Style Feed Why one feed design cannot serve an account with eleven followers and one with sixty million. Push, pull, and the hybrid model that treats celebrities differently. Part 1 · Medium (opens in a new tab)
- Enterprise Gutenberg Blocks: A TypeScript-First Architecture for WordPress at Scale One attribute rename broke 12 blocks without a single error. TypeScript for block attributes, one Webpack bundle for dozens of blocks, and SCSS shared between the frontend and the editor. Medium (opens in a new tab)