Cover the basics and go deeper: "React Router uses the History API to match URLs to components. I code-split per route with React.lazy and use route loaders for data fetching."
Client-side routing intercepts navigation, updates the URL via the History API, and renders the matching component without a full page reload. Key considerations: code splitting per route, handling 404s, protecting authenticated routes, scroll restoration, and deep linking. Strong candidates mention data loading strategies (loaders in React Router v6/Remix) and the UX of loading states.
Fundamental SPA knowledge. Candidates who cannot explain how client-side routing works lack core web development understanding. Those who mention modern features like route loaders show current awareness.