Mark Reinhold runs it, having been there since 1.x days as the core tech lead. He also pushed the move to open source and fast release cycles. But mainly he seems to have recruited and developed good people. I can’t think of a more enduring lead facing more challenges, technical and organizational.
Yes Mark is the Chief Architect with vast responsibility, in addition is Chief Language Architect Brian Goetz [1] and the OpenJDK Amber Project members [2][3].
[1] https://inside.java/u/BrianGoetz/
[2] https://openjdk.org/census#amber
[3] https://openjdk.org/projects/amber/