Even the culture check was a technical interview. Be over prepared and showcase your technical skills to convince the managers. The interview process gradually evolves from enthusiasm to technical expertise.

I had a 20 minute call with their headhunter, who ended up setting a meeting up with a Technical Manager. We clicked and I had a second interview which was also very good. The third and last one, did not go as well, and I actually said no thanks but Darktrace really came around apologized for the miscommunication and I ended up giving them a do-over in the third interview, which I haven't regretted ever since.