After you pass the online tests and the first competency-based interview (for me it was by phone), you get invited to the Shell Recruitment Day (SRD). They put you up in a 4-star hotel and you first meet with your fellow candidates (max 6 ppl) and play some games (not assessed) to get to know each other better and prepare for the next day, where you'll have to work as a team in the group discussion. In the evening there's a classy dinner. Here, you'll get the chance to meet with 2 graduates already on the program, and ask them any questions you have about working for Shell, or tips for the recruitment day.
The next day, the first assessment came at 7.30am- the Etray exercise. Definitely do the Etray practice (link given in the candidate SRD briefing pack) a couple of times before going to the SRD. It's best to work very accurately and effectively through the emails. Don't focus too much on just answering all emails, it's more important that you give the correct answers (and it's ok even if you don't answer all the emails). After the Etray, there's a written task where you have to reply to another email. We only had to provide bullet points, not a fancy essay. So it's important to be concise and take into account all aspects (review the documents given in the Etray exercise again to be sure you include all relevant points).
Next was the group discussion. There was a "breaking news" video on the screen, and we had been asked to come up with a solution to react to the news, together as a team. The time limit was again a pressing matter. It's important to work together, listen to each other and let everyone have a say in the group discussion. Assessors are watching closely to see how you react in this environment. Do you get along well with others, while also being actively involved in the discussion and not just follow the crowd?
After this you go into a room to meet one of the assessors one-on-one for a self-reflection interview. They ask how you think the Etray and the group discussion went, what you think you could've improved on, how would you approach the tasks differently next time, did you learn anything new from the tasks, etc. Here it's important to give honest answers that show that you're a self-aware individual who's always looking to improve. Do not come off as defensive if the interviewer makes an observation about the way you work. Think critically if this is true, and if you agree then just let them know you agree, don't give any excuses.
Then came the case study. You're given (in my opinion) enough time to prepare by reading documents given (this time on paper). Read quickly and retain important information. A good practice for this is to find technical or financial reports/articles that you find difficult, read through them quickly and then summarize their main points (e.g. type a small paragraph in Word). Ok, back to the case study. While reading through the documents, mark the important parts (you're given a marker and pens, and a calculator) and write your own short comments on the documents. Always check the time on the clock! Make sure you have enough time to prepare a 5-minute verbal presentation (or shorter, if you're a concise speaker. Shorter than 5 minutes is better than longer, because they will cut you off). Write down bullet points of your main arguments for choosing a certain recommendation. Also think of potential questions they could ask to attack your recommendation ("why didn't you go with the other option instead of this one?") and prepare answers for them.
After the prep time is over, you're guided into another room to meet 2 assessors. They let you do your presentation (I did mine sitting down, with my notes in front of me), then start asking many questions. Keep calm and answer them as logically and reasonably as you can.
When this was over, we had a lunch break (there were also short coffee breaks in between all the previous exercises). After lunch, there was the final interview. You're sitting across two assessors (different ones from before, because the whole day the 6 assessors rotate so that each one gets to meet each of the candidates.) They ask you competency-based questions similar to the phone interview. So achievement and relationship questions. Be enthusiastic when talking. They will also discuss what career path you see yourself in. Prepare a good answer to let them know you set realistic goals, and you know where you want to go. Finally, prepare good questions to ask at the end of the interview.