Fair warning to skilled engineers: your expertise is irrelevant here. The interviewer lacked fundamental knowledge (couldn't discuss space time complexity) and stubbornly insisted on a suboptimal solution, likely one he memorized (which I also told how to resolve). The conversation revealed his technical insecurity, and it became obvious the decision wasn't based on merit. I'm convinced they operate with a strong ethnic bias and are only interested in hiring their own. A truly disappointing glimpse into unprofessionalism. Also read their reviews on indeed which goes deeper into their unprofessional behaviour.