You will have multiple rounds of interviews (about 8 in total) in a span of 2 to 3 months. The first few interviews are more aligned with your interests and personality to see if you fit in the company culture.
Afterwards, you get a reasonably complex C++ coding exam solving some algorithm puzzles from Codeforces. There is always one question that can not be solved (many times it is the one related to office work) to see if you have the "ability" to want to be perfect and move on. For me, it was one about calculating employee vacation time based on time spent.
You might get different questions, but one I still remember is "B: Card Constructions"
Afterwards, you will have a technical interview talking mainly about C++ programming concepts, metaprogramming, Data-Driven programming, and finally a GPGPU kernel you need to implement for a sum reduction (advice: use a warp shuffle implementation from the internet).
Lastly you will have a final interview with the Owner where you will do a scenario exercise where you get a description of a scenario and you need to mention the dangers, risks, and problems you might see occur from this scenario. (Mainly looking if you can spot dangers in communication styles, or things mentioned form the text).
I really discourage you from applying to the company (see my review on Glassdoor) but if you are truly desperate this is what happened.