I literally wrote a book on Meteor.js and still have to check the manual for stuff all the time. The fact that engineering interviews are essentially roast sessions / pop quizzes is insane.

I interviewed with Snapchat a few years ago and was asked to write a Sudoku solver. Some context: I had never played Sudoku in my life, lol. I came up with a naive (unoptimized, unrefined) solution and didn't get past their third round.