>>12020748Some people they have hired are from CMU and other top universities, some of the curriculum is good.
If you want to learn math then look up Poh-Shen Loh and follow everything he does since he's the US national olympiad coach, see his youtube channel. If you want to learn 'math for job interviews' then you buy AlgoExpert or leetcode grind.
Remember you can always just pay a local grad student to teach you instead of giving all these people your money. They could use your money and likely are better teachers because you interact with them