Frontend

What kind of testing have you done and what tools did you use?

What makes you better than other candidates for this position?

When do you use type assertions (type casting) and what are the risks associated with them?

What are conditional types in TypeScript?

What is Canvas, have you worked with it?

How does HTTP/2 differ from HTTP/1.1?

What is TypeScript type guard and why is it needed?

What happens if you pass a function as an initial value to useState, and why is lazy initialization used?

How does React traverse the Fiber tree and what happens to child components when the parent updates?

What are Web Workers and when are they used?

How do you approach a new complex and poorly defined task: do you evaluate the work and build a plan?

When do you apply React optimizations: immediately or after a problem appears?

What does useCallback do and when is it useful?

Determine the order of console output in the example with synchronous code, Promise.resolve, and two setTimeouts.

What is this in JavaScript? How does this work in regular and arrow functions, how can the context be lost, and how to restore it?

Tell us about your experience working with a monorepo.

What are smart and dumb components? Give an example.

What are mapped types in TypeScript?

How do you find bottlenecks and performance issues in a frontend application?

What is WebSocket and how is it established?