The interview was around 1 hour and the interviewer has almost 6 years of experience in frontend application development.
Question 1: Create a polyfill for the Filter method (Link to the article)
Question 2: Create a polyfill for Object.entries (Link to the article)
Question 3: Create a custom hook that provides a counter that can be used to display on the screen and three buttons play, pause, and reset with functionality in react (Link to the article)
Later after these practical questions, the interviewer tested a few of the conceptual-based questions on React.
Conceptual Question 1: let’s suppose we are running a useEffect for every millisecond, which means 1000 times per second, and updating the count(state) for every millisecond. How many times do you think UI repaint will happen?
Conceptual Question 2: He asked me to explain the shouldCompenentUpdate of class components. the follow-up question for these is to tell the alternate for shouldComponentupdate in functional components which is React.memo(). Later he asked about useMemo and a few other react hooks.
The below video contains FlexCar interview experience.