Bun 1.x in Production: A Complete Migration Guide from Node.js

Bun 1.x in Production: A Complete Migration Guide from Node.js Target: Smashing Magazine / Draft.dev Author: Wilson Xu Word Count: ~2800 words Date: 2026-03-22 Introduction Node.js has been the backbone of server-side JavaScript for over a decade. It has a massive ecosystem, battle-tested stability, and an enormous community. So why would you migrate to Bun? The short answer: speed, simplicity, and a dramatically improved developer experience. Bun is a fast all-in-one JavaScript runtime built from scratch using the JavaScriptCore engine (the same engine Safari uses), written in Zig. It is not just a runtime replacement — it ships with a bundler, test runner, package manager, and native TypeScript support baked in. No configuration, no separate tools to install. This guide is written for teams actively running Node.js in production who want a realistic, no-hype assessment of what migrating to Bun 1.x actually involves. We will cover the HTTP server, file I/O, SQLite, testing, package ma