Step-by-Step: Migrating from Node.js 21 to Bun 1.2 for Your Backend APIs Why Migrate to Bun 1.2? Bun 1.2 is a modern JavaScript runtime built for speed, offering native TypeScript support, a built-in bundler, test runner, and package manager. Compared to Node.js 21, Bun delivers up to 3x faster startup times, lower memory usage, and seamless compatibility with most Node.js APIs. For backend APIs, this translates to reduced infrastructure costs, faster response times, and simpler tooling. Pre-Migration Checklist Before starting the migration, complete these checks to avoid roadblocks: Audit all dependencies: Use bun audit or check the Bun Node.js Compatibility page to confirm support for critical packages. Back up your Node.js 21 project: Create a separate branch or snapshot to revert if needed. Note Node-specific implementations: Identify uses of __dirname , __filename , or custom Node core module polyfills that may need adjustment.…