Anyone with experience increasing a WordPress-site based PWA?

Been asked to investigate creating a Progressive Web App as part of a WordPress website project and am keen to talk to anyone that might have experience. I don’t have a lot of heavy JS experience personally, but have been looking perhaps at Gatsby, but wondering if there’s anything else out there I should be looking at.

Simeon, did you ever make it anywhere in learning? I’m trying to learn/experience the same thing and curious if you made any progress.

Made a basic headless WP site using http://nuxtjs.org but nothing too fancy.