It was followed up by 1. Intro call 2. machine coding round 3. technical discussion 4. hiring manager round. 5. Hr round (cultural fit) each round is knock off round. but honestly the interviewer are already have solution mindset in which he won't accept any new answer if you match his answer and give copy paste view then you are good otherwise you are knock off. I have explained him all the solutions and given him areas of improvement where we can do but time didn't allowed me, he still says this or that are not done. That guy was seriously doing either macro management work or he too good in coding as no one can develop 100% quality code with full expectation until unless they know the problem before or developed it multiple times. Shared the feedback with the HR's. Just an advice to all who are applying please don't give your creative answer try to copy answer from either people with working in cred or check all possible sources from where you can try these question even before you started interview process.

Streamlined, organised and quick. 3 Interview rounds. Algorithmic + Implementation System Design with design choices explanation Hiring manager with past work and projects in depth discussions were great good people open to feedback