Round 1: system design. First the interviewer asked me about my current company’s projects, like how to handle too many requests and multiple writing requests in the same object, etc. Then he asked me to design a mechanism to crawl two (follow up: a lot of) websites. Round 2: coding. Implement a function to add files to a file management system. Round 3: lunch & interview, coding. First question: serialize & deserialize a binary tree. Second question: Write a function to find spam email (emails sent from wrong names like “Micr0s0ft” or “amezon”)