I applied online through their website. The interview process is documented there and takes around 6-8 weeks.
After submitting my application, the technical recruiter sent an email and asked a few questions about my experience. About a week after answering those questions, we had a short preliminary interview via Skype where we briefly discussed my motivation, expectations and experience. After that, the formal interview process started.
First round, was an interview with the team lead and one of the engineers. The goal of that interview was to see if the candidate was a good fit for the team and the company.
Second round was a coding challenge (Codility) and an assessment (Kornferry) that assessed competencies, attributes, and motivations along with verbal, numerical, and logical capacities.
Third round (final round) was a fully technical interview with two engineers where they asked more detailed questions about the coding challenge, software architecture, testing, etc. and then I received an offer.
The recruiter was very helpful throughout the whole process and the interviewers were patient, friendly, and thorough.