I have to echo the sibling comment: just build stuff. I worked on a startup (ended up failing for non-technical reasons, but that's beside the point) where the

I have to echo the sibling comment: just build stuff. I worked on a startup (ended up failing for non-technical reasons, but that's beside the point) where the main application was in Rails, and we had about half a dozen microservices powering various other features. I tried to find SOA-related literature but most of it was impenetrable, enterprise Java type stuff. So we just kinda made it up as we went along, splitting off any services that seemed like it'd work, and that went really well.