It reads to me like he’s using Astra. This is based on me reading the comment, and seeing him say he’s using Astra several times, eg:

  For example, I improved the SOTA on "listing all legal Scrabble moves" by 10x just by prompting Astra over and over to try harder, to aim for <specific performance level>, to "systematically try every method in the literature that seems kind of related," etc.