Turn vague bug reports and hard-to-review pull requests into clear accounts of evidence, decisions, risks, and verification using one worked engineering example.

Learn how HTML element choices affect keyboard behavior, landmarks, forms, and crawlable links through a practical issue-tracker refactor.

Decide which JavaScript belongs in the initial bundle, implement a safe on-demand import, and verify that splitting improves the journey rather than moving the delay to a click.

Start with a real component problem, define a shared contract, test a small pilot, and make changes safe for teams that depend on the system.

Predict when promises, timers, and async functions run. Trace task and microtask order, then see why yielding does not always let the browser paint.
