Optiver Linux Systems Engineer interview questions

There was the initial screening with the recruiter, during which we talked about relocation, the role, and my experience. Following this, they sent a take-home test and gave me a few days to complete it. For some reason, instead of testing as a Linux Systems Engineer, they sent a test labeled for Infrastructure Software Engineer role, though they had previously stated this would be the case without providing a clear explanation as to why. The test consisted of a long-form question, as well as a few coding challenges. The long-form question was fairly generic and didn't give an idea of how detailed they wanted the response to be. It was also strange that they tested mostly programming skills and had no questions on other topics relevant to the Ops-oriented role. However, I dove right in and learned a few things along the way. Unfortunately, although the test software's built-in tests fully passed for each coding challenge, that was insufficient to proceed to the next step in the hiring process. The feedback the recruiter passed along from their hiring team seemed to be quite inaccurate for some my answers, such as stating that a clearly correct regex was incorrect, and they also dinged me for not being detailed enough in the generic long-form question. So I wasn't sure if the feedback was meant for someone else, if they just didn't realize how poorly put together the test was, or if their team/company culture glorifies setting everyone up for failure, but I just let it be. It didn't feel like I would have thrived there anyway if that's how they ran things.