I Failed to Implement the Diameter of a Binary Tree in a Coding Interview

Six months ago I failed a basic coding interview at a FAANG. Yes, I was a Principal Engineer, and yes, I was paid absurd amounts of money, yet I couldn’t implement a diameter of a binary tree as a “warm up” exercise, 10 lines of code. The interviewer was very nice about it, and was equally surprised. You see, I’ve been coding for 35 years, and I am not “rusty” at it, which is a typical excuse for…