Performance work is hard when you’re guessing what’s in your bundle. The bundle analyzer turns it into a visual diff: you can see which dependencies are big and whether code splitting is working. I gate it behind an env var like ANALYZE=true so it’s o

Compression can dramatically reduce payload sizes for JSON and HTML, but it also costs CPU. I enable it with sane defaults and avoid compressing already-compressed content (like images). Compression can also hurt streaming responses and SSE, so I disa

Most security issues aren’t exotic—they’re missing headers and unsafe defaults. helmet gives a sensible baseline: headers that reduce clickjacking risk, tighten content-type sniffing, and improve general browser hardening. I still configure CSP explic

Multipart uploads can blow up memory if you parse them naively. With busboy, I stream file data as it arrives and enforce size limits and content-type checks early. I avoid writing to disk unless I need it; for many flows I stream directly to object s

Counters are classic race-condition bait. If two requests read, increment, and write, you’ll lose updates under load. I prefer letting Postgres do the atomic work with an upsert: INSERT ... ON CONFLICT ... DO UPDATE to increment the existing value. Th

Copying code is a core interaction in a snippets app, and it needs to work reliably across browsers. The modern API is navigator.clipboard.writeText, but it requires HTTPS and permissions in some contexts. I try it first, and if it fails I fall back t

Without a centralized error handler, you end up with a mix of thrown errors, ad-hoc res.status(500) blocks, and inconsistent JSON shapes. I use one Express error middleware that maps known errors to stable codes and logs unknown errors with request co

I don’t want components depending on each other just to show a toast. A tiny event bus (or context) lets any part of the app emit a toast without wiring props through five layers. The important part is keeping the API small—something like show(message

Spinners hide layout shifts and make an app feel slow even when it isn’t. Skeletons preserve layout and give users a sense of progress without jumping content around. I keep skeleton components simple and match the shape of the final UI. One practical

Row-by-row inserts are painfully slow for big ingests. Postgres COPY is a great bulk-ingestion tool, and in Node you can stream into COPY using libraries like pg-copy-streams. The important part is validating before you stream, because once you’re in

Prisma makes it easy to write readable queries, but you can still create N+1 patterns by fetching parents and then fetching children in a loop. I prefer using include or select to get related data in one query when the cardinality is reasonable. I als

The fastest way to surprise yourself in production is ADD COLUMN ... NOT NULL DEFAULT ... on a large table. My safe pattern is: add the column nullable with no default, backfill in batches, then add the NOT NULL constraint. If I need a default for new