I apply via hiring agency. They provided preliminary test which contain basic graphic related questions (Such as resolution, shadowing, textures) which you should answer online. Next day after preliminary test I received a phone call to arrange on site interview.
On site interview is good, they give some time to rest before actual interview and than they start asking general questions (ice break). After that interviewer start asking technical questions.
Questions are not difficult but you have to prepare.
Some math questions.
Graphic and pixels questions (Transparency, decals, shadowing etc)
Interviewer was extremely friendly and helpful.