Blog

Cypress runs inside the browser; Playwright runs outside it. That one architectural split explains the debugging experience, the WebKit story, and why parallelism costs money on one and nothing on the other.

Redis is fast because of specific design decisions — a reactor-pattern event loop, copy-on-write snapshots, compact in-memory encodings — not just because it's in-memory.

Kafka is a distributed commit log, not a message queue. Segments on disk, the ISR, the KRaft controller quorum and zero-copy fetches — and how each one explains a config option you've had to set.

From BGP Anycast routing to tiered cache hierarchies and Surrogate-Key purge — how CDNs actually move traffic from your origin to the nearest edge server.

Your Node.js server calls res.send("hello") and somewhere, 1400 bytes cross the planet in 80 milliseconds and appear correctly in a browser. That's wild. But what actually happens?

One 'use client' at the top of your layout wipes out every performance benefit RSC offers. Learn how to push the boundary to leaf components and keep your server tree intact.

Bun is faster where the runtime layer is the bottleneck — startup, installs — and irrelevant where your database is. And the "native addons don't work" objection is out of date: Bun implements ~95% of N-API. How to make the call without repeating anyone's unsourced benchmark.

Next.js has the ecosystem and Vercel's backing. React Router has a cleaner model for interactive apps and a lighter client bundle. Also: "Remix 3" is now a different framework entirely — here's what that means for the choice.

HTTP/2 replaces ASCII text with a binary framing layer and multiplexes dozens of requests over one TCP connection. Here's what actually happens at the wire level.