I applied online. The process took four months.

It was a very long process that took many months and had me completing many challenges and interviews. I admit that had I not received an offer, I would have been quite upset because it certainly is a lot of time to invest for no guaranteed return. On the other hand, the interviewers were always incredibly nice and supportive and made the entire experience even enjoyable, so I would recommend to other people to apply too.

The admissions process is designed to learn about how you think and solve problems rather than test what information or experience you already have. Some people dislike this because they feel like they are not being evaluated on the exact information needed for the job, but that is something that can always be learned later on. Personally, I like that they test more about the employee's way of thinking than specific knowledge.

I do not want to give anything away, but it is a mix of programming-related questions along with general brain teasers and the like. You really do not need to prepare much; it's not testing any specific knowledge.