STRONGLY DO NOT RECOMMEND SPENDING TIME ON THIS! This is a total waste of time and total disrespect. You get a really big UNPAID assessment task, like designing and writing some utility highly-optimized functions. Designing and writing tree-search. Designing and writing architecture for a small system (like an elevator). Plus unit-tests coverage for all of this. After 2 weeks of ignoring me and my letters I received feedback: "Lack of documentation & comments". Not a single word about tasks or a code I wrote or the architecture I designed, but docs... Remind you, that the tasks themselves are already big enough and require a lot of your time and they are not paid. It's a really bad unfunny joke, not a serious hire process. Strongly recommend you avoid this company.