I had an interview with a recruiter. I told him a bit about my experience but it was at a very high level. Next I had an interview with two engineers from different teams. They mostly asked about the Adyen's formula and some culture questions. Next they sent me a link to a 4-hours HackerRank test. Most of the test required knowing Java and you can't choose a different language. It took me by surprise because at no point during the process did they mention that this position requires knowing Java. They even said the opposite, that it's not a prerequisite for this position. Although I have some experience with it, they never asked me the extent of my experience nor did they say that this test requires understanding concepts that are specific to Java. All in all, it was a waste of time. I put a lot of effort into finding time in my schedule to take this long test and they didn't even bother to have a follow-up interview like other people here mentioned.