I applied for the Tax summer vacation scheme and found the application process appropriately testing - it tried a series of talents vital to succeeding in the industry: mathematical analysis, critical analysis and core competencies in the interview. It began with basic information, why Deloitte etc. Then I was invited to take online tests, if you pass those, you are invited to take the e-tray excercise where you assume the role of a senior associate at a fictional firm, advising a fictional client and answer live emails based on information packs given (no prior knowledge is required). If you pass that you have to write an essay for the client, advising them on a firm to merge with based on a number of factors (though this may vary on the position applying for etc.). After passing those you will be invited to a final interview which is a one-on-one interview for around 1h30 with a Tax Manager, as mentioned earlier, this is largely competency based, but they squeeze in a couple of 'why tax' and 'why Deloitte' questions at the end. I found out 3 working days after that I had got it.