General flow was I applied, and then got an email inviting me to both the assessment and to schedule a role introduction (group meeting with an engineer).
Interview definitely seems more difficult than most, mainly because of the amount of stuff you need to do. Here's a breakdown of what was on it:
1 section on basic math (think percentages, algebra, etc.). 2 minutes, 10 questions. Get as many done as possible.
1 section on logic. Brainteasers such as, "I go to the store to buy an item for the house, where each one costs $1. I tell the cashier I want 600, but it only costs $3. What did I buy?" (We bought house numbers '6', '0', '0'). There were also some regular math word problems sprinkled in as well, so keep that in mind.
1 section on M/MUMPS coding language. I saw lots of people say it's a made-up language, but in reality it's just a really old language developed for medical databases. About 20 questions on these, they give you rules on the language (what variable types do we have, how do we do AND, OR, etc.) and you have to answer questions about them. Take time to make sure you're considering both the current rules as well as previous stated rules for a given question.
1 section is a coding section. 3 Leetcode-style questions, easy-medium difficulty.
Main thing to try is go fast while getting everything right. Easier said than done, but do your best! Also, you do get breaks between section. The 'exam' is done through the Honorlock extension. You'll have to click on 'Start' for a section to begin, but between the sections you can get up and use the bathroom without a time penalty.
There is also a behavioral you do separately. It felt weird, with a few types of questions. For one, you are given a relation between two words (Fish-Rod) and then you are given a third word (Tiger) and a list of options. You then pick the option that makes the most LOGICAL sense to you. Then there are questions that ask about yourself (multiple-choice). What I found weird is that I kept getting forced to give conflicting answers because other options did not align with who I was. You are also given math questions (not hard, algebra/percentages again).
Overall felt it was a bit difficult for a first interview, but also made sense since this was the main technical to do. Got rejected despite doing all LC optimally and doing decently on the other sections. I have heard online that many people get rejected due to the behavioral, but don't take my word for it.
Good luck!