Coding challenge in a language you are comfortable with, you find out what you will be doing on the day and 2 members of the Liberis team will be there to watch/support.
My coding problem was to create a Restful API endpoint, the main criteria they judge is process & confidence, they deduct more points the more they have to chime in and they'll say it's fine if you don't create a working solution to the problem but that isn't true (my feedback stated that 1 of the reasons I didn't pass was that I didn't have a functioning solution even though they said it was fine during the interview).