JetBrains Robotics Engineer interview questions

tl,dr: I don't think the application is worth the time doing the assignement. I've got a first interview with the HR. After, I went to the second interview with the CTO and the HR. Interview went well, both HR and CTO were very nice. I was a little bit worried though because I asked about work-life balance and they answered about wanting "passionnate peoples". They asked me to do an assignement (a path planner on a specific map with ros, implemented in either C++ or python). It took me ~30 hours. Feedback were good but they asked for performance improvements. They asked for performance improvement, I improved the performance of the PRM from 30 seconds to planning average to 4 seconds. Feedback were again very good. They "liked the way I improved the planner and the changes I implemented". Another candidate was taken because he did a better job at the test. While I think the assignement give a very good overview to what you could do at the job, it's very time consumming. Mine took ~30 hours to do. I have to admit that, compared to other job application, being refused felt worse because of the time invested in the application. But again, it's my fault, because I think I invested myself emotionnally way to much into that one. I don't think the application is worth the time assignement, but again, that's just my experience. Whole process, from interview to final refusal, took 2 months. Hr and CTO were nice and professional.