There is the standard phone / video screening interview, the technical (learning your work history) interview, technical / code challenge then towards the final stage interview.
Overall, the scheduling and interview process were informal and mildly unprofessional. For example, the proposed & given interview times were last minute - and were not prepared with your full resume.
Lastly, do note that you're not interviewed by a HR professional, and the question of salary expectations may come up.
