I'm a frontend dev primarily, so I've not looked at implementing GraphQL, and I've only used GraphQL a little bit on the side. I LOVE it and I'd love to be able to use it more! So eh... Those are my opinions 😅
We have a team pioneering GraphQL for one of our Paypal Checkout products. GraphQL is being used on node.js as an orchestrator (mid-tier service) for one of our mobile SDK clients. It is yet to be released, but so far consuming it has been great!! The developer on this project is not online today. But I will definitely bring to his attention, to answer your question in more detail. Cheers!!!