I applied a few times on their website.

1. The recruiter called me to confirm my availability, describe the position (I applied for a few), and appoint me for an initial phone interview.

2. The phone interview was technical to the extreme. Questions were about Java language keywords, Java collections, design patterns, thread safety, JEE 3-tier model, database architecture, and web architecture. The questions were tricky, but the interviewer was supportive. It was a 20-minute intense Q&A.

3. I was invited to an onsite technical interview with international team members, using video conference (English spoken). The project was reviewed, and I was asked a design question to solve a problem. When I solved the problem, they added more complexity. It was a simple question slowly evolving to a complex server-side, multi-threaded database solution. It was an intense experience; the interviewers are sharp and experienced engineers.

4. I was invited to a hands-on Java test with one of the interviewers. The test was about learning existing, frizzed code and extending it with additional functionality. Then it followed with an intense, deep-dive technical interview into the deep and dark corners of Java. Much deeper than the phone interview. I felt great professional respect for the interviewer, and I felt he respected me too.

5. Interview with the direct manager. It was mostly a political and personality interview, assessing my soft skills for working in an open-source environment with top professionals. There were a few technical questions about software language architecture and multi-threading.

6. Interview with HR, assessing my history, motives, soft skills, desires, career, salary, and fitness for an open-source company.

There were 6 at the finals. I believe the final selection was about personal match to the company and open-source development.

How to handle a rejected code submission to an open source project. It was a political question more than a technical question.