Had a pleasure chatting with the team and felt like it would be an incredible culture fit for anyone with a more entrepreneurially oriented attitude. OA wasn't bad, Phone Round had mental math, fermi questions, brainteasers, final round focused on probability and behavioral. Had a very positive experience although I didn't receive an offer.
Test, then an online Interview, and then a final round interview. Pretty easy, just study brain teasers and warm up your brain beforehand. Read "Heard on the Street" and it should be easy.