Do not waste your time. First stage was an HR iterview, than technical one after which I was offered to implement a test assignment. I spent a lot of personal time to complete it. On subsequent interview where we discussed its implementation, it looked like the team was very pleased with it. After this interview, they told me they would return with an answer in approximetly 10 days. They came after 10 days with a response that they are still not able to answer. And, finally, after 1 week more when I wrote them by myself, they sent a refusal from 'no-reply' email. We can conclude that it is better not to take their test assignments, because there is a high chance that you will waste a lot of time and it will not even matter how much effort you put in and how well you do. They apparently considered me for 2.5 weeks as a fallback and at the end they spat at me with a message from the mail that cannot be answered.