thequantguide.com Avis 

I bought the course. It's pretty average. The videos are OK but similar to ones you can find on YouTube for free. I wasn't asked any of the questions from their bank in any interviews. They mostly seem scraped from Glassdoor.

After buying the course I later did more research and it turns out you can't find the people on LinkedIn or any other social media, so I doubt they actually worked in quant. They also seemed to say inconsistent things to people in the intro call (the same guy told to one person he works for JS while he told me he works for Citadel).

When you have an intro call, ask them to give you their full names and proof that they actually work (or worked) for an HFT company. Also ask to speak to someone who has taken the course, got a job thanks to them and can prove that he/she actually now works for an HFT company (they say on their website in the reviews section there have been plenty such people). Ask for hard proof, don't just trust what they say.

If you do more online research, you'll find other people who got scammed by this website, some of them listing hard evidence it's a scam.

Interviewed at SIG (susquehanna) — got asked 4 questions from their videos in my on-site round.

Well worth the investment. I'd recommend to people serious about switching to quant finance

Very valuable feedback with adding projects to my resume; very well structured content that helps with building intuition. I ended up landing 2 summer quant internship offers

This is the only reliable interview question bank I've found on the internet. Got asked 4 questions on my Jane Street on-site interviews that were directly from the list in the betting/strategy section. Their solutions are very thorough and do a great job of walking you through otherwise complex topics.

It's regularly updated with recently asked interview questions.