Unorganized. Unconventional. Lengthy and frustrating. The HR does not know who is who and sent me an invitation email while I was half way through, which is funny. They do not provide any feedback when they want to reject you which is far from a professional hiring process.

Although the people are great, don't apply here unless you are absolutely sure you want this job and no other job as their interview process makes it hard to apply elsewhere. My interview process was quite long (July to September) and when they offered me the job, it was mandatory to accept or decline the offer on the spot. The interview process itself consisted of three tests, two written and one maths test. On top of this, I had six other interviews with various (very kind and knowledgeable) people at the company.