Test taken: Mathematics Admissions Test (MAT)
Number of interviews: 3
Time between interviews: Around 2 days, give or take
Length of interviews: 30 mins each 
Online interview: Yes

For the CS interviews: It was all a lot of hard maths questions! Some interviewers had a little chat at the beginning about the personal statement, and one briefly asked why I wanted to do CS+P, but what took up the bulk of the interview was the maths question(s). I had one or two each interview, where I'd be given some problem on a topic I hadn't seen before, and asked to find some solution (every time I found one they just made the problem harder!). I never finished a question, really, so don't worry if you can't completely exhaust their questions! It felt quite like they were guiding me through the problems, not trying to make things difficult for me, which was nice. For the Philosophy interviews: In one interview I was asked a fairly simple question about two apples being the same that gradually evolved into a much more complex discussion about things existing, though it all progressed very naturally (and as it happened I covered the same topic at one point in my first year!). The other was on logical validity, a concept I admitted that I didn't understand, and so we worked through the definition of it and got onto some harder conundrums about it. Overall these were much more like discussions, and I think there really are no truly wrong answers - as long as you explain and justify your thoughts, and listen to their feedback, you'll do well.

I generally just tried doing a lot of hard maths problems, since that's basically what the computer science interviews are! It was very useful organising some mock interviews myself; one was organised by my head of sixth form with a 2nd-year Oxford student and the other I organised with my further maths teacher. It doesn't matter too much if the other person doesn't know much about the interviews, since a lot of the work you do in them is talking through a hard maths problem without much input (it helps if they know a bit of maths though!). The online mock interviews recorded by the university were also a great help, especially since you can see how other people work through the problems. I'd definitely focus more on preparing for the computer science interviews over the philosophy ones since they don't expect you to know any philosophy before coming here! I admitted in one of my interviews that I knew very little, and we worked through some simpler problems and I got in just fine - definitely focus on the CS side!

Lots of past papers! I think I made it back to about 2015 when going through past papers, but I think doing more wouldn't have hurt. It's especially useful doing them under timed conditions since it helps you to think a bit more quickly - though don't rush either! The Oxford MAT livestream was very useful too; it was a weekly livestream run by the maths department that went through a different topic on the MAT over the Summer. I'd definitely recommend watching that if it runs in your year (which I imagine it will!) or watching through previous years' livestreams otherwise.

A lot of the interview questions you find online are outdated or wrong! I remember seeing questions for computer science like "Explain how GPS works" - I wasn't asked anything about that in the interview and haven't seen anything like it in the degree! The best sources for interview questions would be from the departments/university themselves. Also, try and enjoy them! Obviously, it'll make the experience more pleasant to go through, but the interviews and admissions tests are very similar to the tutorials and exams you do at uni. So it's best to have fun in them (I promise they're less stressful when you get here)! Specifically for philosophy - don't worry about coming up with some totally correct outlook on a problem! Most of these questions have been asked for centuries and nobody's got a good answer yet, so don't worry if a tutor can spot holes in your arguments. Just explain what you're talking about, take in their feedback, and hopefully, you'll find yourself with a more nuanced view on the topic than when you started the interview!