The recruiter reached out after I applied online, and then I completed a coding challenge. The challenge itself wasn't terribly difficult, but with the hour-long time constraint, it was not easy to finish on time. Afterwards, I submitted my code to the recruiter. The next day, she replied to schedule a phone interview with a developer at Jane Street.

The phone interview is the part that is causing me to leave a negative review. After I picked up the phone, and without hardly any introduction, the developer started asking about hash tables. I then gave the answer that basically every developer would know. He then asked me how I would optimize the worst-case lookup time for a HashMap (for when you have collisions). I suggested some things that typically happen in languages like Java to deal with collisions, but these weren't good enough answers for him. He then suggested a BST to store collisions for a bucket. I said, "Ah, then we would have a worst-case lookup time of log n," demonstrating that I did know what a BST was, even if I didn't draw the connection to how they could be used for looking up collisions faster.

It's fair enough if Jane Street wants to reject candidates for not answering this question correctly; that's their decision. The part that bothered me was how it set the scene for the rest of the interview. I talked my way through the entire coding pair without much input from the interviewer at all. If there were glaring mistakes in my code or the overall approach, the guy interviewing me kept his mouth shut, and it was pretty clear that he wasn't paying attention at all. I even asked a clarifying question about an assumption in the problem while I was coding, and I didn't get a response, as he was most likely looking at another screen and not giving me much of his attention.

Like I said, I finished the code pair with little to no input from the developer who was interviewing me. Afterwards, I got to ask some questions. It was pretty general stuff, as I wasn't actually interviewing with a DevOps engineer. I wasn't really left with a great understanding of what the role was, but that doesn't really matter, as a couple of days later I got a generic rejection email.

Coding challenge: Given a robot starting at (0,0) on a Cartesian plane, facing north, a list of coordinates that contain barriers, and a list of instructions that consist of rotating left/right or a number of spots to move, calculate the maximum distance that the robot ever gets from the origin.

Explain hash tables. How would you optimize the worst-case lookup for retrieving an object from a hash table?

Given a list of stock orders which contain a ticker symbol, buy/sell order, and quantity, return a list of the overall quantity of each stock.