STEM fields by and large are the most friendly towards alternative (or complete lack of) education. A well-manicured GitHub, a decent resume, and not looking like an idiot in an interview trumps most college degrees for mid-level developer jobs that aren't Facebook/Google/etc.
I suspect he's pretending all STEM is programming though.
I am not. I would have said programming if I had meant it.
ETA: Ironically enough, I am a non-degree holder (dropout) working in a non-programming STEM field. My bio is a bit out of date since I have indeed gotten out of the data science community.
On a side note, I did find a job with a startup, but that was because of a chance encounter while trolling the right bars every night for 3 weeks looking for that chance. Smiles and handshakes always trump resumes.