First, a phone interview with the recruiter and a take home quiz that was sent to my email. I was given a week to complete a set of very technical questions in broad areas of science (Numerical analysis, Graph theory, Chemistry, Kinetics, Biology). The questions as others who interviewed for this role have mentioned are very hard and time consuming to answer taking the entire week (+80 hours). After submitting the answers a short email followed that we have decided not to proceed with your application with no feedback whatsoever. I asked them to at least let me know what my score was, but they never responded. Here's the thing: Their whole process is quite sketchy. I suspect that this company is crowd sourcing the answers to some actual questions they have and don't know the answers to by exploiting candidates to do the hard work for them and solutions. They might include few questions with known textbook solutions in the whole quiz set to suggest otherwise. Some of the questions in the quiz are very similar to the questions one finds at sites like InnoCentive.com where there are significant monetary rewards for right solutions they post online. I suggest you stay away from this company. They would not value the hard work and long hours you dedicate to their interview process by even providing a basic feedback on your performance, and their practice to run this kind of interview is very abusive to say the least.

After learning a bit about the company, I was prompted to take challenge questions which were related to advanced topics in programing, chemistry, biology, statistics, etc. Scoring high enough will garner a typical 1 day interview with team members in the various teams.