Be balanced: "TypeScript catches entire categories of bugs before runtime and makes refactoring safe. But for a 50-line script or a rapid prototype, the build step and type ceremony slow you down more than they help."
TypeScript benefits: catches type errors at compile time, self-documenting code, better IDE support (autocompletion, refactoring), enforces contracts between modules, and makes large codebases maintainable. Wrong choice: quick prototypes, small scripts, teams unfamiliar with type systems (learning curve), environments where build step is unwanted. Strong candidates discuss: strict mode adoption, the any escape hatch problem, type narrowing, discriminated unions, and the trade-off between type safety and development speed.
Tests practical judgement. Candidates who refuse TypeScript for large projects or insist on it for tiny scripts both lack nuance. Look for experience with gradual adoption in existing codebases.