I applied online. The process took 1 week. I interviewed at Two Sigma (New York, NY) in Feb 2016
Interview
I received an invitation to answer 2 programming questions on Hacker Rank. The total time to complete the problems was two hours, which is plenty of time if you don't have major bugs in your code. Both problems pretty much required good selection and implementation of data structure algorithms and recursion. I completed the exercise in about 1 hour and a half because I encountered a bug that took me a while to figure out. The on-site interview is actually easier than the problems I did on Hacker Rank. The on-site interview consisted of 3 parts: algorithms, architecture (e.g. distributed and parallel algorithms), and a test-driven development. It was my first interview in a while so I messed up undergrad-level CS questions. After interacting with the interviewers and going out on a lunch social I realized it wasn't going to be a great place for me to work in, but that is just personal taste.
Interview questions [1]
Question 1
For the architecture question, Conway's Game of Life algorithm was considered. I was asked to write pseudo code for tackling this problem at a micro-level (e.g. one machine) and a large-scale level (e.g. distributed system).
first interview was 60 minutes long with a leetcode hard question. second interview was 2 back to back 60 minute leetcode hard with emphasis on data structures. each interview had a 5 minute introduction and 10 minute at the end to ask questions
Standard medium difficulty hackerrank. The question involved decoded an encoded string. It was not something I had seen on LeetCode before and I think was unique to the company. The question was not that difficult but I ran out of time right before I could finish answering.
Interview questions [1]
Question 1
Decode a string encoded using a specific encoding algorithm.
It started of with one phone screen, then if you pass you have 2 back to back technicals, then 3 1 hour behaviorals, hiring committee, and management committee. Standard Leetcode and behavioral questions.