I went through a two steps process. First, a simple and very professional phone interview with an HR officer. She ask me about my job experience, how do I use Twitter as a professional tool. A few days after I received an e-mail in order to set an appointment at the local Twitter office (Europe). They gave me the names of the three persons I was going to meet. I talked with them one after another. I had the impression they didn't really expected me to come (¿?) and they forgot to give me the confidentiality document I was supposed to sign but they were quite friendly.