ONE OF THE WORST EXPERIENCES EVER
The issue with writing an interview experience review for Millennium is that they operate based on a pod structure, so the interview process is highly dependent on the PM. For what it's worth, this is my experience with one of the PM's.
I'd submitted my resume to their general quant careers email, and within two weeks a Senior PM reached out to me to see if I'm interested in two particular job postings. Notice that this is a direct reach out by the Senior PM, and not by HR. This is probably a Red Flag #1 to foreshadow what's to come.
Because there are two job postings, he has two separate HackerRank coding assessments. One of them is very LeetCode-ish, while the other one is basically just a data science application of Black-Scholes. The allotted for those two coding assessments combined was 8 hours.
After spending 8 hours over a weekend (I think it really took more like 6 hours combined), the PM said he wants to now move forward with a take-home project. The turnaround time for this take-home project is 1 week. Mind you that by this point, I have NOT spoken to any live human being whether it being phone or video chat. It has just been terse emails between this PM.
The take-home project in itself is Red Flag #2. It's an intraday price prediction exercise. The instructions were horribly written. The Red Flag came at the end of the instructions pdf --- in addition to submitting a source code, a written document to explain your logic, the PM also wants "feedback" about this very take-home project instruction. Why do they need "feedback" about things like, do you have enough data, do you have enough computing time, are the instructions clear, etc? Is it because they are use this take-home project repetitively but don't actually hire? I'd actually spent the full one week to work on the project and actually even constructed some perhaps novel feature engineering ideas.
I submitted my project on time one week later. Received no acknowledgement of the acceptance of my materials, but it's understandable. One more week passes by and I follow up. No response. One additional week passes by, so by now two weeks since submission, I follow up again. No response. By now, which is well over two months since submission, I'm sure I've been ghosted.
All in all, this has been one of the most unprofessional interview experiences ever. This guy effectively had used the coding challenge to screen me for quality, then used the take-home project to brain-rape me for ideas. If a candidate had spent 8 hours + 1 week for an interview process, even if things don't pan out, at the very least you could write a short email to let the candidate know.
IN ALL: I'd be highly cautious for an interview process that eats up so much of your time but that consumes zero time on the interviewer's end.