Node has been the answer since 2010. By 2026, Bun and Deno are mature enough that the choice is real for new projects. Each has a specific sweet spot; the wrong choice means either fighting the ecosystem or paying performance penalty.
Node — the default
Massive ecosystem, ubiquitous deployment, mature tooling. Performance has improved through V8 updates but still trails Bun. Worker threads, native modules, every npm package works. Right answer unless you have a specific reason to deviate.
Bun — startup speed and runtime perf
Built on JavaScriptCore (faster startup than V8). Native TypeScript without transpile step. 2-3x faster HTTP serving on benchmarks. Bundler, test runner, and package manager built in. Right for: latency-sensitive services, dev-loop speed. Ecosystem compatibility is good (most npm works) but watch for native module quirks.
Deno — security model and standards alignment
Built-in TypeScript. URL-based imports (no node_modules). Permission system (--allow-net, --allow-read). Standard library aligned with web platform. Right for: scripts, edge functions, scenarios where you want explicit permission boundaries. Less ecosystem reach than Bun.
Edge runtimes (Workers, Vercel Edge)
V8 isolate-based. Strict APIs (no Node-specific APIs). Cold start measured in microseconds. Right for: edge functions. Wrong for: anything needing native modules, long-running connections, file system access.
Decision summary
New service, performance-critical: Bun. Edge functions: platform runtime. Scripts and permission-sensitive: Deno. Anything else: Node. Migrating existing Node app to Bun: usually works, sometimes painful — test thoroughly.