The process consists of 2 stages - in the first you get an assignement and in the second you talk face to face. The assignement consists of few questions like writing some stored procedures and providing desing of abstract system in line with given requirements. Even if assignemts may seem to be difficult you should try to do them as you can, because only part of applicants do try to solve them, so if you provide it even not perfect, you still have a chance.