You have a talk with the recruiter first. This is just to found out your motivation. The second interview was for me online with the trainer to go a bit more in depth about knowledge and eagerness. Finally you have 1 interview on the office with a java test to see your skill level at that time. If everything is positive you can have a last interview with the CEO, this is just a "formality" but don't take it too lightly. Also because of the relationship between rp-one and nexios don't apply for both