SciTec Numerical Algorithms Software Engineer interview questions

Low compensation. After a brief phone they quickly moved to a coding challenge, 1 week lead time. They rejected me and would not provide any feedback. Rather unprofessional given the time sink and the fact that they ask candidates to perform work-like activities without compensation. I think their algorithms/software job ads are somewhat fake. The same ones have been flying for a while. Judging by other reviews, I think they're fishing for the cheapest candidate.