Server-Sent Events (SSE) in Node.js
A dashboard I shipped last quarter needed a job-progress bar that ticked from 0 to 100 as a background worker chewed through a queue. My first instinct was a WebSocket. I wired up the server, the…
Common Node.js errors · quick reference
All error fixes →| Error | What it means / fix |
|---|---|
| UnhandledRejection | Fix UnhandledPromiseRejection in Node.js It’s 2 a.m., the pager goes off, and your Node 22 service is in a restart loop. The logs show one line — a rejection reason — then… |
| SELF_SIGNED_CERT | Fix self-signed certificate in certificate chain You ship a service that calls an internal billing API over HTTPS. Works on your laptop at home. Monday morning you’re back on the office VPN, you npm… |
| fetch failed | Fix ‘fetch failed’ in Node.js It’s 2:15 on a Friday, a webhook handler that has run clean for months starts throwing on one upstream, and your logs show this and nothing else: TypeError:… |
| CORS | How to fix the CORS error in Express It’s 4 on a Friday, the API works perfectly in Postman, and your React dev server on localhost:5173 calling the Express API on localhost:3000 throws a wall of… |
| ERESOLVE | npm ERESOLVE unable to resolve dependency tree You bumped React from 18 to 19 on a Friday afternoon, ran npm install, and the terminal filled with red. The deploy you promised for Monday now hinges… |
| ESM import | Cannot use import statement outside a module It was 11pm and a teammate had just merged a “tiny” dependency bump. CI went red on every service that imported our shared logging package. The stack trace… |
Tutorials & how-tos
All tutorials →
Comparisons & benchmarks
All comparisons →
Sequelize vs Prisma vs TypeORM in 2026: the Node.js ORM benchmark and the pick I’d make
I've shipped APIs on all three. Sequelize from 2017 to 2020 on a payments API that's still in production. TypeORM through 2021 on a logistics dashboard, where the migration generator broke twice and burned a sprint each time.…
Performance & Architecture
All recipes →
errors
Recipe
Sentry for Node.js APIs: Express errors, traces, releases
Set up Sentry for Node.js and Express with error capture, tracing, releases, source maps, PII scrubbing, sampling, and production alert hygiene.
Node.js
Recipe
OpenTelemetry in Node.js: production traces that help
OpenTelemetry in Node.js with HTTP, Express or Fastify, pg, Prisma, Redis, request IDs, trace propagation, sampling, and the incident view that matters.
Node.js
Recipe
PostgreSQL connection pooling in Node.js: the bug that shows up at scale
PostgreSQL connection pooling in Node.js with pg, Prisma, PgBouncer, serverless limits, transaction pooling traps, and the dashboard I check first.
Docker
Recipe
Node.js microservices architecture: the patterns that actually held in production
I helped a logistics startup split a Node.js monolith into seven services in 2022 and watched them spend the next eight months untangling a distributed monolith. The services…
Express
Recipe
Node.js API security in 2026: the checklist I run before pushing to prod
I leaked a logistics company’s internal API for eleven days. Not a customer-facing one — an admin endpoint that returned every shipment’s tracking number, recipient address, and carrier…
Node.js
Recipe
Node.js cluster vs worker threads: which one when (and the trap I fell into)
I had a Node.js video-processing API throwing 503s every time someone uploaded a 4K clip. The default fix everyone reaches for — cluster.fork() across cores — actually made…
