I applied online. The process took 1 day. I interviewed at Hudson River Trading (Montreal, QC) in Jan 2023
Interview
You have 2 hours to answer 4 algorithms questions on CodeSignal. A lot more difficult than other SWE internships I had on CodeSignal. I only got 2 done out of four
automatically received email for OA right after applying, had to take within two weeks after application
OA was 2-3 leetcode mediums / hards
online interview on zoom after passing OA
Interview questions [1]
Question 1
Asked some abstract system design questions, like giving some api or method and asking a way to implement some system efficiently.
But the interviewer was late by 5 mins, sped through the explanation verbally without any written text, and answered in a very irritated voice when I asked back for clarifications. Would't want to work with them
1 hour, 15 minute per interview, very dense, very rapid follow ups for understanding.
Fist round was algorithms, balanced tree
Second was algorithms, K-d tree internals
Third was OS; I bombed this since I didn't take OS yet, but it was fine
Fourh was networking protocols and reliability
Interview questions [1]
Question 1
For example, the balanced tree started as basically, "do you know how to use a BBST and how to traverse it" to, "how can I rebuild it", to then, reasoning about *real* internals (such as walking a subsection of the binary tree; walking a subtree is O(K + nlogn) even if random access to all nodes is Klog(n)
I applied online. The process took 5 weeks. I interviewed at Hudson River Trading in Sep 2025
Interview
Started with an OA, (which I believed was not automatic). Then, proceeded to two phone screening rounds, which tested on general C++ programming, and then got grilled on C++ fundamentals and how computers work under the hood. Got into the superday, which is onsite and has 3 total rounds. Didn't make it past second round, but they are all live coding. Be prepared for heavy implementation style questions, and talk through the design of the algorithms and data structures you use.