Frontend

Please tell about your development experience, what do you consider important to mention?

Implement a function that creates an array of promises and executes them sequentially using a loop method. If a promise resolves successfully, continue with the next; if a reject occurs, handle the error with catch. When should the final resolve be called if all promises succeed?

How do you feel about artificial intelligence? Do you use it in work and everyday life?

How do you feel about situations where requirements are vague, missing, or you need to clarify details yourself with colleagues, designers, analysts? Does the need to independently refine tasks and communicate with stakeholders scare you?

How do you feel about hot tasks that require you to switch quickly and do something fast? Does this mode of work scare you?

Write an implementation of the isPalindrome function that takes a string and checks whether it is a palindrome (reads the same from left to right and right to left). The function should return true or false.

Write an implementation of the delay function that takes the number of milliseconds and returns a Promise that resolves after the specified time.

Implement a function (similar to pipe/compose) that, on the first call, takes a set of functions, and on the second call — a number, then applies the passed functions to this number sequentially, passing the result of the previous function to the next. For example, a function like inc, nested multiple times, should increment the number sequentially.

What is a polyfill? Have you ever written polyfills?

Write a polyfill for the String startsWith method, which appeared in ES6, using only ES5 features (without let/const, arrow functions, etc.), i.e., through prototype inheritance.

Name the performance metrics (Web Vitals) — one is related to user interaction with the page, the other is related to UI rendering. What do they measure?

Conduct a code review of a pull request with a single diff file on a React component (Book component using useEffect, data fetch, displaying popular and all books). Find and comment on all issues: hook rule violations, lack of error handling in fetch, absence of AbortController, no response status check, inline styles, missing key in map, no checks for empty arrays, need for memoization (useMemo), extracting fetch logic into a custom hook/component, etc. Also, how to implement a condition so that the request only runs when the isBest flag is true?

Tell us about the new features introduced in the ES6 (ES2015) standard in JavaScript.