I applied online. The process took 2 weeks. I interviewed at Hudson River Trading (New York, NY) in Aug 2024
Interview
Codesignal OA (regular GCA assesment, must be done in c++)
Then phone which is 45 minutes with an engineer going over some systems and c++ trivia. Asked follow up questions about responses to test knowledge
OA - codility and then live interview rounds, pretty difficult they want someone who actually knows things deeply and on a low level such that the dev has full control of what's going on until the memory level and how do kernels work