This is an elimination-style interview process. If you fail one round, you do not proceed.

Interviews 1 and 2 were coding rounds with one behavioral question each. They asked me to talk about a project and the technology it used. It was strange because they kept asking how my company does X, Y, and Z. The questions were straight from LeetCode; one was hard and the other was medium.

There were two System Design and Behavioral Rounds:

1. This interviewer asked me to talk about a project. I started giving him context, and he cut me off and asked for the queries-per-second (QPS) of the system. I told him, and he seemed really upset. He asked about another project on my resume, and I told him the QPS for that one. He seemed quite uninterested for the rest of the interview. I discussed the project in more detail, and he criticized many aspects of it, such as the database choice or the traffic load. At 30 minutes, he gave a system design question: "Suppose you're selling 100 limited edition new iPhones for $100 each as a promotion, and you want to sell them on a first-come, first-served basis. You anticipate 100 million people will be interested. How do you design the system?"

2. This interviewer asked me to talk about a project. He interrupted and asked what the bottleneck in the system was, how I found it, and how I solved it. The System Design question was: Build Twitter.

Suppose you're selling 100 limited edition new iPhones for $100 each as a promotion and you want to sell them first-come-first-serve. You anticipate 100 million people will be interested. How do you design the system?