First round interview was a screening call with a recruiter discussing my background. Discussed experience, salary expectations, etc. Second round interview was a Leetcode style coding task on a call with an engineer. The question was breadth-first search based. I was subsequently invited for the final round (2 behavioural interviews + 1 systems design interview) which was would take 3 hours. At this point I was asked my availability, I provided it and was never contacted again. Prior to being ghosted the recruiter was very responsive, generally giving feedback and details on the next stage within 24 hours of the previous interview. The recruiter's calendar wasn't very accomodating for UK timezone, despite interviewing for UK roles.