Its very rigorous. I applied - automatically got invited to do the Culture Questionnaire. I got an automatic email inviting me to do the cognitive tests. Did that and didn't get through, despite having passed.
Still in the process so cannot fully say everything. Great experience so far however still in the assessment phase (questionnaires online - pretty straightforward). The emails you receive each time to tell you that you've reached the next step are soothing.
Interview questions [1]
Question 1
playful, patient or assertive. Have to pick the most and the least important.