Zoom interview with 2 lead developers. Was asked to implement a circular buffer class. Some questions were asked about the design decisions and for some code they asked if performance could be improved. Also some questions were asked about concurrency

Face to face interview with the group manager, lasted 1.5 hours. The man started as very cordial and easy-going, immediately breaking the ice. 5 minutes were dedicated to questions regarding system design, not hard questions for the experienced. The rest of the 85 minutes were a free chat, with the interviewer sharing much personal irrelevant info and asking me some borderline personal questions. Very unprofessional. Throughout the interview there was no push back on his part to indicate there is any mismatch, and he concluded saying that next I'll have 2 further interviews of technical nature and finally a meeting with the VP. Much to my surprise, the recruiter called 3 days later saying it's a no go, without any explanation.