Web Development Advanced

Client-side state with React/useState, server state with sessions and JWT, cookies vs localStorage, and caching strategies.

Resource-oriented design, HTTP methods and status codes, idempotism, versioning, pagination, and error response patterns.

How to push real-time updates from server to browser: polling, long polling, SSE, and WebSockets — with tradeoffs and use cases.

Single-page apps vs multi-page apps — tradeoffs in bundle size, SEO, time-to-interactive, and development complexity.

An event loop repeatedly selects ready work and runs callbacks or tasks.

Follow the key state changes and boundary checks involved in async code still runs on an event loop.

An interactive concept flow for async code still runs on an event loop, from its assumptions through the main operation and boundary checks.

A retry repeats work after the caller cannot determine whether an earlier attempt completed.

Threat-model a request by tracing sensitive data, user authority, trust boundaries, and the controls that limit abuse.

Follow a login attempt through rate limits, password-hash verification, authorization context, and a protected session cookie.

Follow request limits, account lookup, password verification, session rotation, and later authorization checks.

A security prompt about password verifiers, salts, offline guessing, authentication, session creation, and authorization.

A cache stores reusable results near the request path to reduce repeated work or latency.

An interactive concept flow for caching and routing change the request path, from its assumptions through the main operation and boundary checks.