Node.js Developer Job Description Template (2026)

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# Node.js Developer — Job Description

## Role summary
A Node.js Developer builds production services in Node 20+ with strict TypeScript: HTTP APIs in NestJS, Express, or Fastify, streaming pipelines, background workers in BullMQ or Temporal, and real-time features over WebSockets. They know the event loop well enough to debug a 200ms p99 stall, understand why Buffer allocations show up in heap snapshots, and ship async code that does not silently swallow rejections. They are Node-specific engineers — not generalist backend devs dabbling in JavaScript.

## Responsibilities
- Build HTTP APIs in NestJS, Express, or Fastify with strict TypeScript and Zod/valibot-validated request/response schemas end-to-end.
- Debug event loop stalls, unhandled promise rejections, and memory leaks using clinic.js, --inspect, heap snapshots, and async_hooks.
- Write streaming code correctly: piping large responses, handling backpressure, aborting on client disconnect, avoiding full-buffer reads on big payloads.
- Implement background job processing with BullMQ, Agenda, or Temporal including idempotent handlers, retries with exponential backoff, and dead-letter queues.
- Model data in PostgreSQL or MongoDB through Prisma, Drizzle, TypeORM, or Mongoose with reversible migrations and query plan awareness.
- Build WebSocket and SSE channels (Socket.IO, ws, uWebSockets.js) with reconnection, room broadcasting, and sticky-session handling behind a load balancer.
- Use Worker threads or child processes for CPU-bound work rather than blocking the main loop; know when Node is the wrong tool.
- Containerize services with multi-stage Dockerfiles (distroless or alpine), right-size memory limits, and avoid the "full Ubuntu base image" trap.
- Instrument with OpenTelemetry, Pino structured JSON logs, and Datadog or New Relic APM; tie alerts to user-facing SLOs.
- Manage the npm / pnpm dependency graph defensively: audit regularly, pin transitive deps that matter, and avoid adding 400 packages for a one-line utility.
- Run on-call for services they own; write runbooks covering restart procedures, known error codes, and rollback steps.

## Must-have skills
- 4+ years shipping production Node.js services in TypeScript, ideally in at least one of NestJS, Fastify, or Express.
- Deep understanding of the event loop: microtasks vs macrotasks, process.nextTick, libuv thread pool, and how CPU work blocks I/O.
- Node Streams: Readable/Writable/Transform, backpressure, piping, and why full-buffering a large upload is wrong.
- PostgreSQL or MongoDB at a level past "the ORM handles it": query plan reading, index strategy, transaction isolation.
- Async patterns: Promise.all vs Promise.allSettled, error propagation, avoiding the floating-promise bug, AbortController for cancellation.
- Docker multi-stage builds, production Node image hardening, and memory-limit awareness (V8 heap vs container limit).
- npm or pnpm fluency including lockfile discipline, audit remediation, and evaluating package health before adding dependencies.
- Testing with Jest or Vitest, plus Supertest for HTTP and Testcontainers for integration runs.

## Nice-to-have skills
- NestJS at depth: dynamic modules, interceptors, custom decorators, microservice transport layer.
- Contributions to the Node or npm ecosystem (packages, core PRs, runtime tooling).
- Deno or Bun exposure and an informed opinion on when to reach for them.
- gRPC / Protobuf in Node for internal service calls.
- Temporal, Inngest, or similar durable execution frameworks.
- Low-level work: native addons, N-API, or performance-critical V8 tuning.

## Tools and technology
- Node.js 20+ / TypeScript
- NestJS / Fastify / Express
- Prisma or Drizzle
- PostgreSQL & Redis
- BullMQ / Temporal
- Socket.IO or ws
- Pino + OpenTelemetry
- Docker (multi-stage)
- Jest / Vitest / Supertest
- clinic.js + 0x

## Reporting structure
Reports to the Engineering Manager or Backend Lead. Collaborates with frontend engineers on API contracts, with DevOps on Node runtime configuration and container sizing, and with SRE on on-call escalation paths.

## Success metrics (KPIs)
- Event loop p95 delay under 50ms on production nodes, tracked in APM.
- Zero unhandled promise rejections in production logs over a rolling 30 days.
- API p95 latency under 200ms on owned endpoints; p99 under 500ms.
- Job queue success rate above 99.5% excluding expected business failures.
- Memory usage stable under load — no sawtooth leaks visible in Datadog over a week.
- npm audit: zero unresolved high/critical vulnerabilities in owned services.