Two 1-hour-long phone interviews, followed by two on-site days, working within in the company.
The interviewers' team is very mixed; apparently, they employ very few "professional" programmers and prefer to re-invent or otherwise ignore some of the basics.
If they don't like you for any reason, they simply chose to never call back and cut all the communication. They ask prospects for some professional communication skills - I guess, management has finally noticed the lack of it in their current employees.