A9.com Data Science Engineer interview questions

Submitted CV online. Got a call from team tech lead. Had 1/2 hour interview on the work I was doing for my PhD. Then, over the next 3 weeks, two 1 hour interviews each, covering fairly challenging coding and machine learning questions. Got called for a full day onsite interview. Gave a 45 minutes presentation on one of my research papers. Then had 4 interviews (1 hour each) with software engineers and data scientists, covering machine learning topics, standard coding questions and some difficult puzzles. Had a discussion with team lead during lunch about the team. Got an offer within 2 days. Did not negotiate salary since I was quite happy with the offer