I applied through university. The process took 1 day. I interviewed at Optiver (Auckland, Auckland)
Interview
The event was held in a lecture theatre on campus. We were sat down for around 30 minutes while they told us why we should work for them, and then offered a test for those interested in the trader internship. This test consisted of an 80 question, 8 minute arithmetic test, and a pattern recognition test.
The arithmetic test was fairly easy, but long. Questions were just basic integer arithmetic with a few fractions, and each has a multi choice answer. The questions are easy, it's purely a matter of speed.
The pattern test was harder. You get a sequence of 5 numbers, and then pick the 6th from 4 possibilities. I have forgotten exactly, but I think it was about 20 questions in 20 minutes. For a few of these I couldn't make out any pattern, while for a few others there were in fact totally justifiable reasons to pick 2 of the 4 options, and you just have to guess which pattern they thought they wanted.
About a week later I got a phone call telling me I did not pass. I was not told my score, or the required score, despite my asking. At no point has it been explained to me why these tests are a good metric for finding a trader. I also will not be able to reapply, and again they have not told me the reasons behind this policy.
spent about 1.5 months pretty much purely dedicated to preparing for interviews for all the pre-penultimate programs (Optiver, IMC, JS, SIG, Citadel, etc). I used these resources:
Green book (Really good starter but I got bored of it after a few weeks)
EverythingQuant (Went through literally every single interview prep question, went through the interview guides, and completed the probability course just to make sure I covered all bases)
Briefly read through this guide
Watched coding Jesus in my spare time (not sure if this helped directly lmao but he’s a great creator and very informative)
Mental math test, beat the odds, online puzzle like games etc online, brain teasers during physical interview and a behavioral interview where they want to assess how competitive and assertive you are.
OA was weird and hard. there was only three sections (i think) this year compared to 5 last year. questions are weird and I don't know how they can judge your ability base on that.