The whole process included two phone screens and a five-interview onsite, all 45 minutes each.

The first phone screen was all about coding, with two problems to solve on a shared CoderPad document.

The second, conversely, focused on Unix systems internals. The interviewer asked about a project from my resume and we delved into the systems aspects from there.

The onsite was composed of five interviews:

• Systems Design: How to design a very abstract system. The problem starts very broad and generic (e.g., design a pub/sub system) and needs to be narrowed down to details during the interview (storage & bandwidth calculation; distributed consensus and network partition tolerance; DDoS and bot protection and mitigation).
• Coding: Similar to the first phone screen.
• Systems: Again, similar to the second phone screen, also including systems troubleshooting (e.g., "You receive a report that a system is unresponsive, what do you do?").
• Network: Similar to systems design, but on network stack knowledge (e.g., what's the first packet that your laptop sends out when it boots?).
• Soft Skills: SBI questions about your past work experience.

Overall, the interview was of average difficulty and fun to perform.

Design a system that stores and retrieves images for Facebook.