Other than the technical skills you mentioned in your resume, they also focused on knowing you as a person, whether you can handle pressure, can you keep a work-life balance, and what are things that excite you.
1st (Co-Founder) Hiring manager roundabout yourself, and kind of experiences
2nd (Senior Software Engineer) DS-Algo
3rd (Senior Software Engineer) In-depth questions about the technologies you have worked on, system design.
4th (Director of Engineering) System-design
5th (CTO/Co-Founder) Behavioral Questions