Typically process before the assessment day. Graduates are actually the ones who mark and assess your video interviews, I thought mine went horrendously and I managed to get through so just keep going.
Assessment day
As an introduction we had to pick a movie star to play the role of our life. Personally, I think its really important to make sure you pick someone whom is relevant (i.e. said person would play me because they've played a vast amount of role and I believe I'm quite a diverse individual) as opposed to anything too relaxed (someone said Seth Rogen because they are 'quite chilled', definitely not a good choice). This section is not marked so I wouldn't go overboard, just a justified answer in a relaxed form.
Next we had our first group task which involved building a robot (there were three more sections but we didn't get past the original task). Each of us took a turn to see how the robot needs to be laid out, and then we would describe it to the group without showing them the picture or pointing. This section isn't about how fast you complete it as a group, or how well you perform individually, the most important thing is how well you interact with your team. Don't be that person who tries to dominate the task.
Presentations are next. Relax, take your time, make sure you don't use your slides as references too much. It is a chance to impress so bring in relevant notes if you have any which help to demonstrate how you're genuinely interested in technology.
Last group task is about 4/5 sheets of information, you sit down and are given a role (Financial director/HR/etc etc), the main point is to select which Fujitsu location would be best for your role. Make sure you fully understand your role and look for all the relevant information that will affect your decision, write them all down and formulate some good points which justify your answer. Listen to people when they are talking, let people speak but equally get your point across in a polite manner.
Lunch follows. They'll pick the people they want to go for the final stage of the process.
Lastly, there is an interview. I believe these will be tailored to your CV so there isn't too much advice I can give you. I would just say try to show enthusiasm in the interview and take your time answering the questions, think about the question before giving an answer.
I spoke to a graduate who said the hiring managers are looking more towards personalities rather than your skills. From my experiences on the day and how I approached it, I think you have to prove you're motivated for the role, use lunch as part of the assessment day rather than just a casual chat to the other individuals on the day. Listen closely at the start for who's hiring for which position, figure out the one you like the sound of best and make sure you go up to them and ask questions about the role. They know you won't know what their role actually entails so don't worry about asking silly questions.