What does full-stack developer mean.
Common understanding is that full-stack is a guy/gal who can create both - visual, client facing part of the app and backed side, where most of data processing and domain logic is contained. But this is not enough, because it is missing one crucial ingredient. How to wire both sides together.

In fact, true full-stack - in my opinion - have to also understand also operations side of things. Which is managing servers, log aggregation, CI pipelines, configuring webservers, databases, virtualization etc.