Sometimes you just need ‘only one worker does this thing at a time’, and building distributed locks from scratch is risky. Postgres advisory locks are a pragmatic option when your DB is already the source of truth. I derive a deterministic lock key (l

React Suspense handles async operations declaratively, showing fallback UI while data loads. With frameworks like Relay or React Query's experimental Suspense mode, components throw promises when data isn't ready, triggering the nearest Suspense bound

Tokio's spawn creates a new async task that runs concurrently on the runtime's thread pool. Unlike OS threads, tasks are lightweight (kilobytes of memory) and scheduled cooperatively. Each task must be 'static and Send, meaning it can't borrow local v

I separate liveness from readiness because they answer different questions. Liveness is “is the process alive enough to respond?” and should be cheap; readiness is “can this instance take traffic?” and can include dependency checks like DB connectivit

ExoPlayer is a flexible media player supporting diverse formats and protocols. I create instances with ExoPlayer.Builder(context).build() and configure with MediaItem. Setting player.setMediaItem() and player.prepare() initializes playback. PlayerView

Custom validation rules encapsulate complex validation logic in reusable classes. I create rule classes implementing ValidationRule with a validate() method receiving the attribute, value, and fail closure. Rules access databases, call APIs, or perfor

After a POST, Turbo behaves best when you redirect with 303 See Other (Rails symbol :see_other). This avoids the browser trying to re-submit the POST when the user refreshes, and it plays nicely with Turbo Drive’s navigation semantics. I use it especi

Performance optimization reduces load times and improves user experience. I use code splitting to break bundles into smaller chunks loaded on demand. React's lazy() and Suspense enable component-level code splitting. Dynamic import() loads modules asy

Deploying Django to production requires many configuration changes. I set DEBUG=False and configure ALLOWED_HOSTS. Security settings include SECURE_SSL_REDIRECT, SESSION_COOKIE_SECURE, CSRF_COOKIE_SECURE. I use environment variables for secrets. Stati

Prometheus collects and stores time-series metrics via a pull model. It scrapes /metrics endpoints at configured intervals. The prometheus.yml defines scrape_configs with target discovery. static_configs list fixed targets while kubernetes_sd_configs

React Hooks enable state and lifecycle features in function components. I use useState to add stateful values that persist between renders. The useEffect hook handles side effects like data fetching, subscriptions, and DOM manipulation. Dependencies a

Project Lombok generates common Java code via annotations at compile-time. @Data creates getters, setters, toString, equals, and hashCode. @Builder implements the builder pattern. @Slf4j provides logger instances. @NoArgsConstructor and @AllArgsConstr