Two things. First, what are your career goals? You say you have them, but not knowing what you are trying to do, it's hard to tell whether you are getting ready for it or now. Do you want to build your own startup? Join a large tech company as a developer? A researcher? Do you want to become employee 1 at a startup? Do you want to go into management?

Second, if you are happy with your employer, stick with them, at least until a good opportunity comes along. It's rare to find people you like working with.

In my personal experience, pet projects and general hacking advanced my career much more than any project an employer threw at me. In fact, most of the projects I worked on for an employer were driven by experience I had acquired on my own time: "hey, I think we should build a highly available MySQL cluster over WAN. I have done this before and it'd be perfect for this application" or "hey, I'd can create a small C program to spoof source IP addresses in UDP packets to simplify transitioning from one server to another" or "hey, let's put our entire server configuration into puppet" or "hey, let's package everything into .deb packages". In other words, I play with tech, then bring it to my employer (now client as I am a contractor) and some of it sticks, not the other way around.