I applied online. The process took 1 day. I interviewed at The Technology Partnership (Leeds, England) in Nov 2017
Interview
25 minute mathematics test to begin with. Most questions were straightforward, really shouldn't pose any problems for STEM students. Then, two employees interviewed me, asking generic CV questions and one statistical question (3 bags). Overall, less than 1 hours in total.
Interview questions [1]
Question 1
There are three bags, one contains only red marbles, one contains only green marbles and the last contains both red and green. You do not know how many marbles are in each bag. Each of the bags is incorrectly labelled. How many times do you have to draw to figure out the correct labels of each bag?