I applied through university. The process took 2 days. I interviewed at Optiver (Toronto, ON) in Sept 2015
Interview
They came to our campus and did an info session, candidates that were interested in the position were asked to take a 8-minute 80 questions math test (only + - x /, very hard to complete 100%). Right after the info session I was told that I got selected for a formal interview on the next day.
On the second day, I did interview with HR, very easy, asked about why I wanted to be a trader, why do I want to join this particular company. Things got tough with the technical interview, it was all math brain-teasers questions (what day would it be in 10 or 1000 years). They expect you to solve it in a quick and accurate manner.
Interview questions [1]
Question 1
How many levels can you build with 52 cards? (a deck of card)
EV of throwing a dice, EV of the sum of two dices after you throw 1 time, 400 times. How would you make a market based on that?
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.