I had an interview through a referral.

I received an email to schedule two phone interviews.

Both interviews included an algorithmic question, which I had to code in Google Docs as the interviewer observed.

The second interview also included a non-coding question where the interviewer described a requirement, and I had to explain how I would design and implement the system at scale.

Design a system where a series of events get recorded.

Each event has a timestamp.

We want to have a page that shows the number of events that have occurred within the past minute, hour, 24 hours, and so on.