Why We Ditched Node for Bun in 2026 (And Why You Should Too)

Source: Dev.to

Why We Switched to Bun

• All‑in‑one binary – Bun handles package management, TypeScript compilation, testing, and bundling without additional tools.
• Native TypeScript – .ts files run out of the box; no ts-node or tsx needed.
• Unified tooling – bun test is up to 20× faster than Jest and requires no extra configuration.
• Enterprise stability – Following its acquisition by Anthropic, Bun now offers production‑grade reliability and supports >95 % of Node APIs, including complex native modules (buffer, fs, path, etc.).

ElysiaJS + Bun: A Perfect Pair

Elysia is a Bun‑first backend framework built on Web Standard APIs (Fetch, Request, Response). Its design leverages Bun’s low‑level performance on the JavaScriptCore engine, delivering:

• Staggering throughput – Benchmarks show >250 k requests / sec, making traditional Express/Node services feel sluggish.
• Zero framework tax – Because Elysia uses native Web APIs, there’s virtually no overhead.
• End‑to‑end type safety – Types flow automatically from server to client via Eden Treaty, eliminating manual synchronization.

“With Bun + Elysia we finally reached the ‘single binary’ dream. Our backend now handles everything—from the database driver to the HTTP server—with one tool.”

Benchmarks & Cost Impact

• Serverless savings – Switching Lambda functions to Bun cut execution duration by 35 %, directly lowering AWS costs.
• CI/CD acceleration – Dependency installation with bun install is 20–40× faster than npm/yarn/pnpm, shrinking monorepo build times from ~30 min to under 5 min.

Migration Steps

1. Swap the package manager

   # In your existing project
   bun install

   bun install is a drop‑in replacement for npm install.

2. Run tests with Bun

   bun test

   Observe the immediate speed improvement.

3. Update start scripts
   Change entries like node index.js to bun index.ts in package.json.

These steps let you adopt Bun incrementally without a full rewrite.

Looking Ahead

Node isn’t “bad,” but in 2026 it feels like using a heavy manual typewriter in a world of high‑speed digital keyboards. The ecosystem has matured, and Bun now offers the performance, tooling, and stability needed for modern, high‑concurrency applications.

Further Reading

• Node vs Deno vs Bun: Performance & JavaScript runtime comparison – a 2026 benchmark video that visualizes raw speed differences between the runtimes.