JSON.stringify is the default for every internal service call, but on high-throughput RPC it burns CPU and inflates payloads. Here is how MessagePack replaces it, with Node.js benchmarks, Express middleware code, and the migration path that does not break your public API.
Depth limiting does not stop expensive GraphQL queries. A shallow query with wide list arguments can still exhaust your database and OOM your API. Here is a practical complexity-scoring implementation that rejects abusive queries before they touch a resolver, plus the adversarial test cases that prove it works.
A malformed request slipped past JSON parsing and wrote a null into a required column, causing a cascade of 500s that took two hours to clean up. Here is the Zod validation layer that stops bad input at the API boundary, with the TypeScript integration, custom refinements, and error formatting that makes client integrations painless.
Offset pagination looks fine on page one and falls apart on page two hundred. Here is the exact SQL and Node.js code to replace it with cursor-based pagination that stays fast, avoids duplicate rows, and survives concurrent writes.
Your "just POST to the callback URL" webhooks are creating angry customers, retry storms, and silent data loss. Here is the architecture — queue, circuit breaker, dead-letter, and backoff — that turns fire-and-forget HTTP into a delivery system you can monitor and trust.
A valid webhook signature only proves who signed the payload, not that the request is fresh. Build a replay-safe Node.js webhook handler with raw-body verification, timestamp windows, idempotency, and atomic Redis locks.
Webhook retries silently double-charge customers, double-create resources, and turn one ticket into a refund spreadsheet. Here is the 30-line Postgres-backed middleware that makes any handler safe to retry — plus the hammer-test that proves it works.
gRPC is faster, smaller, strongly typed, and has worse browser support and harder debugging. The decision is workload-specific. Here is the honest comparison: where gRPC genuinely wins, where REST stays the right choice, and the connect-rpc middle ground that resolves most of the trade-offs.
Most teams write the API, then write the OpenAPI spec, then watch them diverge until the docs are useless. The fix is to make the spec the source of truth — generate types, validation, mocks, and clients from it. Here is the workflow that survives, and the tools that make it tractable.
Server-sent events are a 1.5KB drop-in for streaming notifications, progress, and live updates — and they work through every proxy and CDN that already handles HTTP. WebSockets are the right tool for genuine bidirectional, low-latency traffic. Here is the decision tree and the implementation patterns for each.
The “sliding window” rate limiter every tutorial shows you breaks at scale. Token bucket is the algorithm real APIs use because it allows bursts without exceeding the average rate. Here is a 30-line Lua-on-Redis implementation, the failure modes to test for, and the headers you should be returning to clients.
Most API developers think “HTTP caching” means putting things in Redis. The browser, the CDN, and your reverse proxy already implement a four-decade-old caching protocol — you just have to set the right headers. Here is the cheat-sheet of Cache-Control, ETag, Last-Modified, and the conditional-request flow that makes JSON endpoints feel instant.