UI Component Design and Implementation Questions

Capture the full lifecycle of designing implementing and hardening user interface components for production. This includes implementing interactive widgets such as autocomplete with API integration and keyboard navigation star rating controls accessible dropdowns and complex form widgets with validation and sanitization. It also covers larger UI patterns such as search and filter interfaces paginated or infinite scrolling lists and virtualization for performance. Interviewers should expect discussion of accessibility best practices focus management and ARIA attributes handling loading error and empty states mobile considerations keyboard interactions debouncing and throttling user input and strategies for testing and observing component behavior in integration. Candidates should demonstrate how they reason about state placement reuse performance trade offs and edge case handling in real products.