Instead of asking for the usual documents like a cv or reference letters, the job description asked for a detailed description of a problem that was solved in the last two years. This was followed by a friendly phone interview with the CEO, asking about motivation and past experiences.
After that came the on-site interview, that consisted of a single talk with some of the current developers and the CEO. Interesting enough, there wasn't too much focus on the applicant or his career, but instead almost all questions revolved around specific details of the problem described in the initial email. Overall the tone was very different from the phone interview, to point where it got almost rude and disrespectful. I guess that is what they refer to as "developer grilling".
In summary, it was surely the worst interview process I've ever participated in, but I still think its a decent company. The chances of getting hired with a good salary without connections to the existing employees are extremely low in my opinion, so think carefully if you want to spend your time on this.