1st: HR Discussion
This would be a normal discussion asking your background, work experience, and salary expectations.
2nd: Technical Discussion
This would be an interview with their technical guy asking a few ruby and rails questions and some database schema problems. These are average level questions.
3rd: Code Exercise
You need to work on a ruby exercise building a plain ruby app.
It has two parts. They have estimated complete exercise to 12-16 hours. But it takes 40-50 hours approx. Although they give enough time to complete it.
4th: Interview with CEO
This round is just to grill you with irrelevant questions and then reject you. They need a guy who can work both as a developer and product manager and can lead a team also. But they can't even pay $3k for 5 years experienced RoR developer.
After spending 50 hours on their exercise, and the whole process almost took 1 month, they ask me to join in lesser than my current salary, even if they asked my current and expected salary in the first HR discussion.