Highcon Systems Backend Developer interview questions

For a relatively small startup situated in a rural industrial zone and a fairly ugly building they have an incredibly convoluted recruitment process. I had to go through: phone screening, timed online coding test, interview with team lead, another test with writing code on paper?!, interview with R&D manager and the cherry on top, interview with the VP R&D who stated that since he's 'not a programmer' he's going to quiz me with 'engineering style' questions and then proceeded to grill me on topics ranging from calculus to spatial reasoning, I felt like I was back in school again. My advice is stay clear away, not worth your time or energy, unless you like endless bizzare interview cycles but even then there are far better companies out there that do that sort of thing