Sure thing, just keep it tight and don’t let any of that data leak past the edge of the browser. Here’s a quick recipe: 1. **Never store secrets in the code** – drop any API keys, tokens, or passwords out of the repo and into a server‑side env. If it has to go somewhere on the client, use a short‑lived, signed token that expires fast. 2. **Use HTTPS everywhere** – enforce TLS 1.2+ and pin the certificates if you can. Nothing gets past the network layer if it’s all encrypted. 3. **Apply Content‑Security‑Policy (CSP)** – block inline scripts, only allow trusted sources, and use nonce or hash for any needed inline code. That stops XSS which is the usual leak vector. 4. **Minimize exposed data** – send only the fields you need. Strip any PII before it hits the network. 5. **Hash sensitive values before sending** – use a client‑side hash (SHA‑256 is fine) if you need to verify something locally, but don’t rely on it for auth. Keep the salt on the server. 6. **Avoid eval and dynamic imports** – those let attackers inject code. Stick to static imports and well‑known modules. 7. **Audit third‑party libs** – use a lockfile, lock to a known good commit, and keep the old, deprecated libs in a separate folder for nostalgia. 8. **Rate‑limit and detect anomalies** – if a single client is spamming the endpoint, block it. 9. **Test in isolation** – run the app in a sandboxed iframe with strict sandbox attributes, then integrate. 10. **Continuous monitoring** – watch the commit history, set up a simple script that scans for any new strings that look like secrets, and fail the build if it finds one. That’s the core loop. Throw a couple of unit tests on each boundary, stay caffeine‑fed, and you’ll keep the leaks at bay. Let me know if you want a deeper dive on any step.