State Management

Static Site Generation (SSG) is a rendering strategy where HTML pages are pre-built at build time rather than generated on each request. The resulting static files can be served from a CDN with extremely fast load times and minimal server infrastructure. Frameworks like Next.js, Gatsby, and Astro support SSG, often combined with Incremental Static Regeneration (ISR) to update specific pages in the background without rebuilding the entire site.

Observability is the ability to understand the internal state of a system by examining its external outputs — primarily logs, metrics, and traces (the "three pillars"). Unlike basic monitoring that checks predefined thresholds, observability enables you to ask arbitrary questions about system behavior and debug novel issues. Tools like Grafana, Datadog, and OpenTelemetry provide automated collection and correlation of telemetry data across distributed services.

Accessibility (often abbreviated a11y) is the practice of designing and building websites and apps so they can be used by everyone, including people with visual, motor, auditory, or cognitive disabilities. This involves proper semantic markup, keyboard navigation support, sufficient color contrast, and screen reader compatibility. Beyond being an ethical responsibility, accessibility is increasingly a legal requirement in many jurisdictions.

A linter is a static analysis tool that automatically scans source code for syntax errors, style violations, potential bugs, and anti-patterns without executing the code. Popular linters include ESLint for JavaScript/TypeScript, Pylint for Python, and Stylelint for CSS. Linters are typically integrated into CI pipelines and editor plugins, enforcing consistent code quality across a team with zero manual effort.

React's Context API provides a way to pass data through the component tree without manually threading props through every intermediate level. You create a context with `createContext`, wrap a subtree with a `Provider`, and consume the value anywhere below with `useContext`. It's ideal for global concerns like themes, authentication state, or locale, but should be used judiciously since any change to context value re-renders all consuming components.

A canary release is a deployment strategy where a new version is gradually rolled out to a small subset of users before reaching the full audience. Automated monitoring compares error rates, latency, and key metrics between the canary and the stable version. If the canary performs well, traffic is incrementally shifted; if anomalies are detected, the release is automatically rolled back, minimizing the blast radius of potential issues.