I was contacted by a recruited who offered me a contract mostly Java backend position. Firstly they gave me 1 hour hackerrank test which had 3 tasks, 1st was typical task to find pair in an array which sums to X number. 2 others were small about OOP stuff. 2nd round was 1:1 teleconference interview, the guy asked me questions about different skills and technologies, it was pretty relaxed and friendly and sometimes he was even sorry about Red Hat policy to ask it lol. 3rd and final round was 90 mins on-site whiteboard interview (I'm personally against whiteboards), but before it half of time was behavior questions. A lot of them. I wasn't really ready for it. On whiteboard was a known issue about finding all 1 in 0/1 two-dimension array and they make it harder after first step - if you see 1 it means all numbers to the right and bottom will be also 1s so you should find efficiently blocks of 1s. It could be done using pseudo-code but I used real one.