The harsh truth of working at Google is that in the end you are moving protobufs from one place to another. They have the most talented people in the world but those people still have to do some boring engineering work.
Can you believe that people at Google still have to, like, eat lunch and stuff? And talk to each other? The coffee is the same damn color every day too.
Maybe there's a place, somewhere, for the purest-of-the-pure non-boringest thoughts.
Sandstorm.io doesn't use protobuf, it uses Cap'n Proto, which was designed to replace protobuf.
Fun fact: The Zanzibar project was started in ~2011 specifically to replace my main project at the time, which was trying to solve the same problems. Apparently, some senior engineers felt letting me work on core infrastructure was too dangerous. They succeeded in turning my project into a lame duck and making me quit, which is when I then started working on Cap'n Proto and Sandstorm.io. In retrospect I'm glad it happened.
Yeah... Google is not always the most fun place to work on big infrastructure projects.
The point is you're writing mostly business logic and glue. You get a server request, you transform it with some logic, call some other servers, combine the responses and run some more logic, and return a response.
The scalability and interesting work has been factored out and handed off to infrastructure teams that build stuff like this auth framework, load balancers, highly scalable databases, data center cluster management tools, etc.
Which really is the smart way to do it. To the extent that you can stand on the shoulders of giants who've basically made scalability the default, you are free to focus on what you're actually trying to build. The only downside is if all the interesting engineering challenges are already solved for you, the remainder might not that be that interesting to people who enjoy engineering challenges.