Never be surprised if you meet with something that seems to oppose you. – Epictetus
Reflection
Quality is not the shine. It is what holds under pressure: time, messy input, the stranger who never read your notes.
Every line you write carries a claim. It says this will hold. It says it will not harm. It says you can trust me with your work and your users. That is an ethical promise as much as a technical one.
Good code reads well. Great code resists misuse. It narrows what it trusts. It makes intent visible. It fails in ways that do not spill secrets or corrupt the state. It shows its limits at the edges where harm can enter.
You do not become careful by adding more. You become careful by drawing a clear border between what you know and what you will verify. Name the assumptions. Test them where they matter. Let protection, not hope, carry the weight.
Today's Insight
Quality proves itself under pressure. Protection is the proof.
Action Steps
- Draw the line of trust - Pick one request path. Mark every untrusted input. Validate at the entry point with a strict schema. Prefer allowlists. Assert your invariants at each boundary. If it does not parse, stop it there.
- Align runtime with compile time - Enable strict TypeScript. Add small runtime validators at edges so types and checks agree. Turn hidden assumptions into executable checks.
- Lock the defaults - Set Secure, HttpOnly, and SameSite on cookies. Keep tokens short-lived. Deny by default on routes and components that gate data. Remove public endpoints that no longer serve. Set a basic Content Security Policy that forbids inline scripts and restricts sources.
- Harden the React surface - Skip dangerouslySetInnerHTML. If user HTML is unavoidable, sanitize on the server. Add an Error Boundary that keeps context, hides secrets, and offers a clear recovery path. Use structured logs with a private trace ID, never raw data.
- Prove the riskiest path - Ship a thin end-to-end flow that crosses your most fragile join. Exercise contracts under real conditions. On failure, stop cleanly and return a private trace ID. In the PR, include a one-line edge promise and the test that proves it.
Consider This
If a stranger followed the straightest line through your feature, where would they win today?
What is the smallest guard you can ship now that will turn that win into a clean stop tomorrow?