I was interviewed by a senior engineer, he start with introduction and basic questions in javascript like data types, hoisting, closures, promise, event loop, etc. I answered all of them. Then he gave a array based problem to be solved using javascript. I did solve half of it but he only gave 10 minutes. After 10 minutes, he was like let's move to next problem. He then asked me questions on react, he asked me basic react questions which I answered well. He asked me to write a polyfill for useState(). I wrote it but for this he expected little different. For this as well he gave me 10 minutes. For the last 10 minutes, he asked to create a new react project and write a counter with start, pause, reset/stop functionality I did write most of the logic. Due to time crunch I wrote 1 line incorrect and code was not working. The interviewer didn't even provide any hint. He had his mouth shut. When he asked me to stop and paste the code into Google doc, after that he opened his mouth and told you need to change this line. Although it was really embarrasing mistake, tech interviewers need to understand it is code pairing round. Not a good interviewer I guess.