Not sure how this is related to HATEOAS, but having one api backend to front several private services is a pretty common pattern. But as a data point, I can tel

Not sure how this is related to HATEOAS, but having one api backend to front several private services is a pretty common pattern. But as a data point, I can tell you that with us using a react frontend to talk to a nodejs graphql backend that also fronts private services, our nodejs graphql backend is usually below 300mb of ram. At any rate, it sounds like your spring boot app combined with your network topology is the constraint, good luck chipping away at it.