I've managed to go through all the stages, which took about 2 months. All the interviewers was quite polite and the technical steps made sense to me. Unfortunately, when I got the job offer and accepted it, the recruiter did never get back to me to send the contract, so basically, the company wasted money and our time.
It was a shame because in that time I really wanted to work at Netcracker. However, got an offer from other company that suited better. Hope you could refine the hiring process to avoid loosing interested candidates.