Contacted by recruiter, then HR of two sigma. First is the phone screen, which lasted for 30 minutes. Basically just introduction of the company. Forgot the details but no real question. Then a 2-hour code test. They emailed you two questions, and in 2 hours you need to email the solution back to them. Two questions for me: 1. given a list of string (numbers and words), sort words in alphabetical order and numbers are in numerical order. 2. Sync data among multiple data centers. I think I did pretty well but I did not pass.