How full is your stack? It really depends.
I have friends deploying real-time systems to chips, and know developers writing artificial intelligence code, there is somebody submitting code to Linux kernel or nodejs, and somebody is creating a to-do app right now.
For whatever reason I never understood this notion of a full stack developer. On the other hand I don't believe in front-end developers, or back-end developers or whatever end developers either.
A good developer could figure out what is needed and what's the best way of doing it. In my mind, measuring people by skills is reducing their potential usefulness to a box we want to put them in.
One thing that is more important than discussing stacks is becoming really good at figuring things out on the fly.
Technology will evolve, there always be new programming languages and frameworks. You might want to stop chasing the latest tools and rather become excellent at figuring stuff out.