Book: TypeScript in Production — Tooling, Build, and Library Authoring Across Runtimes

Also by me: The TypeScript Library — the 5-book collection

My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools

Me: xgabriel.com | GitHub

You've seen it. A project switches its dev loop from `tsc-watch

node --loader to a single bun run src/index.ts . The cold start drops from three seconds to two hundred milliseconds. Hot edits feel weightless. The team ships the change, deletes the watcher, and moves on. A week later a PR lands that introduces a real type error. A Promise gets returned where the caller expects User . CI is green. The runtime is happy. The bug ships. Production gets a .then is not a function (or worse, a silent undefined`) ten minutes after deploy.

Teams misread what Bun actually does with their TypeScript.

Bun runs .ts and .tsx files without a build step. That is

true.…