I applied through my university and received an on-campus first-round interview. The interview was supposed to last 30 minutes but lasted an hour and a half instead.

He asked me what he called a PM question: "Measure the volume of traffic across a bridge during rush hour." Then, he asked me a coding question: "Longest subsequence."

I didn't finish, so he told me to send the code to him in an email follow-up. He requested two versions:

• One that ran in O(n^2) time
• Another that ran in O(n) time

It was pretty high-stress, and we debated a lot about methods. My interviewer spent time at the end to give me life advice. He said he would recommend me for a second-round interview, but I wasn't accepted for one.

Unfortunate, but I learned a lot. What an interview!

Given the speed of cars across a bridge, measure the volume of the traffic.