TypeScript — Senior Interview Prep

Type-level depth for a senior React/Vue + TypeScript interview. Not “what is string” — the parts that come up under “you wrote this — explain it” or “narrow this type without an as.”

Files

How an interviewer probes TypeScript depth

• “Type this without any” — exercises generics, conditional types, narrowing.
• “Why is your value typed never?” — exercises distributive conditionals or empty-union narrowing.
• “Reimplement Pick<T, K> from scratch” — exercises mapped types + keyof.
• “What does satisfies give you that as doesn’t?” — exercises preservation of literal types and ergonomics vs assertion.
• “Your forwardRef’d generic component lost its generic parameter — why?” — exercises React typing nuances.

Hit those, you’re senior. Stumble on them, you’re mid.

Cross-references

• React-specific typing patterns: Typing React Components (plus React for React semantics)
• Backend Python typing for contrast: Typing

External resources

• GeeksforGeeks — TypeScript interview questions