Hey Tom! When I think of GitHub, I think of Rails. If you were building a new SaaS product today, would you still use server-generated HTML (w/ js sprinkles, as DHH likes to say), or would you lean toward heavier clientside javascript?
I would probably start with a React frontend and GraphQL backend and then optimize from there. Rails is awesome and I owe a lot to it, but the world has changed a lot in the last decade and the modularization and data binding that React/GraphQL offers is too compelling to ignore.