Very easy and relaxed (back in 2018). Had a first call with the R&D team lead, followed by a written test (very easy), and a follow up call with Sean, the director. Nothing to worry about.

It was split into five parts and it was very thorough. First part covered a written assignment specific to the job title. Second part was an one-on-one interview with the HR representative which went extraordinarily well. Next two parts were other one-on-one interviews with both Co-Founders of the company, one of which was more thorough and more detailed and asked similar questions as the HR representative. Last part was a final one-on-one interview with the person that supervises the specific job title and it was more specific about what I will do at the new job and what exactly will be my role in the company.