The Great JavaScript Runtime Debate
When we rebuilt our analytics platform last year, we faced a critical decision:
Should we stick with Node.js, bet on Deno, or go all-in on Bun?
After 6 months of testing, migrating, and debugging, here’s what we learned—and which runtime won our stack.
1. The Contenders
🥇 Node.js: The Veteran
✔ Mature ecosystem (1.3M+ packages)
✔ Proven at scale (Netflix, PayPal, LinkedIn)
✔ Full observability (APM, logging, profiling)
🚀 Deno: The Secure Upstart
✔ Built-in TypeScript (no config needed)
✔ Security by default (explicit permissions)
✔ Modern tooling (deno compile, deno test)
⚡ Bun: The Speed Demon
✔ Blazing fast (3x quicker than Node in benchmarks)
✔ All-in-one toolkit (bundler, test runner, package manager)
✔ Node.js compatibility (most apps work out of the box)
2. Benchmark Battles
| Test | Node.js | Deno | Bun |
|---|---|---|---|
| Cold start (ms) | 120 | 85 | 32 |
npm install time | 12s | N/A | 0.4s |
| HTTP req/sec | 8,000 | 9,200 | 28,000 |
| Memory usage (MB) | 210 | 180 | 95 |
Tests on AWS EC2 t3.xlarge, Node 20, Deno 1.37, Bun 1.0
3. Real-World Tradeoffs
🔧 Developer Experience
- Bun won (zero-config testing, built-in bundler)
- Deno frustrated us (limited VS Code debugging)
- Node.js felt outdated (
node_modulesbloat)
🛡️ Security
- Deno won (explicit file/network permissions)
- Bun was surprisingly good (limited attack surface)
- Node.js required extra hardening
📦 Ecosystem
- Node.js won (every package just works)
- Bun was 90% compatible (
bcryptfailed) - Deno struggled (many npm packages needed patches)
4. The Verdict
🏆 Winner: Bun (for our use case)
- Why? Raw speed + dev experience outweighed ecosystem gaps.
- Compromise: We still use Node.js for some legacy microservices.
🥈 Runner-Up: Node.js
- When we use it: Projects needing
sharp,prisma, or Kubernetes maturity.
🥉 Honorable Mention: Deno
- Best for: Internal tools where security matters most.
5. Migration Tips
✔ Start small (try Bun on a non-critical service first)
✔ Profile before switching (Bun’s speed varies by workload)
✔ Keep Node.js as a fallback (for problematic dependencies)
Key Takeaways
🔹 Bun is fastest, but not perfect (watch for native module issues).
🔹 Node.js still dominates for complex, large-scale apps.
🔹 Deno shines for security-first projects.
Which runtime are you betting on? Have you tried migrating?
Top comments (0)