I applied online. The process took 3 months. I interviewed at IBM (London, England) in Jan 2015
Interview
2 group exercises
stay on after lunch for personal interviews if successful and had more personal questions. This was of average difficulty and gave good experience for future interviews some were very difficult
Phone interview first, and then one week later for the face interview. Need to write some coding for search data on twitter. There is no one answer. You can write any idea you have.
There was a long application form with a full education history list, three motivation questions with reasonably long answers and a few competency based questions drawing on past experience-a chance to expand on what's on your C.V. After this there are psychometric tests in numeracy and verbal reasoning
Interview questions [1]
Question 1
Didn't make it to interview-the matrigma tests are pretty tough