I applied online. First I did an online test called "Values Fit". The test included questions about GSK values and was relatively easy without quantitative questions. After I passed the test, I had a phone interview with a 3rd party HR company followed by the initial interview with GSK HR. Questions during the interview were pretty usual competency based interview questions like "Give me an example of a time when you overcame a difficulty with innovation/changed your teammates' opinion/entered a new challenging environment and succeed?"
It took 35 mins and I got another phone call in 4 days for an invitation to a presentation for the Assessment Center. At the end of the presentation they gave us a booklet for a case study and told us to study it before AC. Assessment Center took the whole day (8 to 5) and observers came from headquarters in London. The exercises were in the following order; Group discussion (about the case), presentation & Q&A (on a different case that was given us there), mockup interview (after reading another case we played the role of a HR director interviewing a project manager about the problems given in the case) and lastly a 30 min interview (questions were the same as the initial interview with the local HR director) with the HR directors from HQ. After the AC i got a final call for a meeting with the Turkey HR director. I was expecting them to make me an offer since I'd passed all the application stages they stated in the beginning. However it was unexpectedly an interview and the questions were "Why HR?" "Would you prefer a commercial role in the following stages of your career?" "Why do you think HR is important?" etc. I assume this extra interview was because of the difference between GSK global and GSK Turkey. Moreover i felt the final interview questions implied that the HR director wasn't convinced that having a MBA was a good fit for the HR position. Other than the Turkey specific part my overall application experience was quite positive and pleasant.