- Vue – Watchers: watch and watchEffect
For the side effects a computed must not do. `watch` with a getter source, the `immediate` and `deep` options and what each really costs, `watchEffect` and how it collects dependencies for you, cleaning up so a stale request cannot overwrite a fresh one, and the demo app's rule that the URL — not component state — is the single source of truth a watcher reacts to.
- FastAPI – Interview Questions
The questions a FastAPI role actually asks, answered against the eighteen lessons before this one. Why type hints do the validating, def versus async def and what happens to each, how dependency injection is tested, where a transaction begins and ends, what BackgroundTasks does not promise, and how a request is traced in production. Short answers, with the reasoning behind them.
- Vue – Computed Properties
Derived state that caches. Why a computed beats a method for anything a template reads more than once, how caching is invalidated, writable computeds with a getter and a setter, and the rule that keeps them predictable — a computed must be pure, so anything that fetches or mutates belongs in a watcher instead.
- FastAPI – Getting It Into Production
From a working image to something serving users. Workers and what they cost in database connections, a reverse proxy in front, configuration and secrets from the environment, running migrations as a step rather than at boot, and rolling out without dropping requests. Plus what to check first when it works locally and not in the cluster.
- AWS – Secrets Manager and Parameter Store
Two services do this job and the right answer is usually the cheaper one. Parameter Store SecureString versus Secrets Manager, compared on the three things that differ: rotation, cross-account access, and price per secret per month. How to read one from a Lambda without shipping a key, caching so you are not billed per invocation, and why an environment variable holding a secret is visible in the console.