[_wt8k]

I want to learn more about HoTT and constructive math, but I probably have to go to CMU to go deep into that.

At Northeastern, I'll probably explore systems programming languages (I know that Amal Ahmed published a foundations of Rust paper) and gradual typing.

[xiaolingxiao]

Hah I was interested in something similar at one point. The PL community is pretty small, if you go to one of these Haskell hackathons you'll meet plenty of them. There used to be one held at Penn (Hack-phi) but that may have ended. Boston Haskell hackathon is still going I believe, and there's many meetups in NY. So going to these places and meet tons of people is one way to secure your own uck. And I echo what the other person has said, your narrow focus on niche topic may have put you in a harder category. Admission officers have very specific buckets they put you in, in this category you may have been competing against math wizes from abroad.