LMAX Group SRE/DevOps Engineer interview questions

The process started straightforward and then became extremely exhausting. First round was a 30 minute call with HR. No issues there. Second round was with a couple of members of the technical team via Zoom. First issue with this was that the call was done blind (not face-to-face), so any pauses while I was thinking just came across like long silences, and a couple of times there were "are you still there?" questions asked. This interview didn't really have anything to do with my CV/experience. The JD specifically called out wanting someone with cloud experience and I was very clear about my background, but the technical testing was related to extremely low-level init.d and linux boot knowledge. This is obviously fine for traditional SRE type roles, but the JD didn't really mention this (only that someone with some linux knowledge is a bonus). This interview went on for 90 minutes and the questioning got increasingly complex (basically, keep asking me to go deeper until I just don't know any more), but then didn't leave any opportunity for me to talk about any of my own skills and experience. Third round, another zoom-based interview (though luckily with camera enabled this time), containing CTO and the same two engineers from the previous round. I was told prior to this interview that I would be asked more questions about my experience. NOPE. More increasingly low-level questioning about another very specific topic (what happens during a HTTP request?) The questioning was literally expecting you to understand the instruction sets being utilised as part of a TCP connection. I don't know how anyone who isn't a senior/principal network engineer would know this stuff. It was frankly ridiculous and very much came across like they were just trying to show off how clever they were. They didn't ask other questions, it was just this one single line of questioning so if you didn't know, it was just a series of "I don't know" all the way down - no chance to prove yourself on other topics. By the end, I was so exhausted and demoralised from the questioning that in the 10 minutes they gave me at the end to talk about my actual experience, I felt like I didn't really give decent answers because I just wanted it to be over. This round was another 90-120 minutes, so I think in all it was about 4 hours of interviews, with 3.5 hours being incredibly intense technical questioning. I get that LMAX are a fintech and so need the best engineers, but the way they go about interviewing (at least for SRE/Cloud/DevOps type roles) is terrible. I called the recruiter before they even had the time to give feedback and withdrew. It wouldn't have mattered if they offered a job to me - no way I was going to take it.