Interviewed as an experienced hire, I got the interview through a recruiting agency. First phone interview with hiring manager, went through previous experience and some behavioral questions. Good connection, he ended the conversation giving me some tips for the next round.
2nd round I was flown into The Hague and participated in an individual assessment which consisted of a case scenario which I had 2 hours to prepare and a presentation of 10 mins based on a general business strategic recommendation. Next was another phone interview (in the office) with HR, again mainly behavioral.
I was exhausted after an entire day interviewing, doing the assessment, etc but worthwhile.
I had applied as a graduate earlier and found the recruiting process for experienced hires much more logical as you're basically assessed as an individual competing for a specific role, not one in a bunch.
Advice is document yourself extensively on Shell and on the hard and soft skills required and map them to your previous experience, in detail.