After clearing a technical elimination interview, there were 5 technical and 1 managerial round, totaling 7 interviews.

The manager likely reviewed my resume for the first time during the interview and stated I lacked the required practical experience in one area. Consequently, I was down-leveled by two notches, despite my work experience matching over 90% of their requirements.

Other companies typically hold a brief managerial round before any other interviews. This allows for a conversation between the manager and candidate to assess relevant practical experience.

They could have avoided wasting 7 hours of my time and countless preparation hours, in addition to their employees' time, by conducting these basic discussions earlier.

Mostly focused around data structures and concurrency. They give a lot more importance to concurrency than other companies.