First, had a call with the recruiter. The second step was a case study to implement a simple android project. Then had a chat with two android engineers. and one of them was the team lead. Then I got the offer. All interviewers were really cool and friendly. also, they raised the offer couple of times to have me. I wish I could accept the offer but because of some personal problems, I had to return to my home country so I rejected the offer after all :(