First of all, I'd like to congratulate the recruitment team of this company, they sure know what they are doing and how to make you feel special during the whole recruitment process, their excitement about their company is highly contagious!
I applied through a very well known Website for developers, a few days later I was invited to an initial phone call with one of their recruiters, the phone call lasted for about 1 hour and the person who called me was really helpful and explained me everything about the company, the profile they were looking for and the recruitment process.
After the initial phone call I was invited to a technical test related to the technologies I would use in the position, the test can be made on your own time and it took me about 6 hours to complete (you have 2 days to finish it).
The test was marked in less than 48 hours and then I was invited to an interview with two of their senior developers. Since I lived abroad, the interview took place via Skype. It lasted for about 1h and 30 minutes so we had plenty of time to talk about my profile, the position and the company. They were really nice and helpful and made me feel like I should be working with them.
After the Skype interview, I was invited to a face to face interview in their London office , the company paid for all travel expenses which was a really nice gesture (thank you!)
I did a first interview with the head of human resources. The interview lasted for about 1h and 30 minutes. The person who interviewed me was great and took a lot of time to explain me about the origins of the company, the current situation and future plans, she had a lot of energy and again her excitement about the company was very contagious.
After a nice lunch with one of their human resources managers, I had the final interview with the VP of engineering.
This was the most difficult part of the process, we talked briefly about my profile and the position as well as some of the technologies they were using and then I was asked some standard (kind of abstract) interview questions, here is where you have to shine as it will be the measure used against other candidates for the same position, you are supposed to take your time and go deep into the answer so if you suck at interviews like myself, here is where you are likely to fail!
A couple of days after the face to face interview I received a call from the person who managed my application and he took almost 30 minutes to explain me the feedback I received during every step of the process and why I didn't pass the interview which was a really nice thing to do.