I am rapidly approaching the three month anniversary of me starting my new job. It has been a very interesting timespan. I've learned a ton about the actual nuts and bolts of large software projects:

My skills with C++ have dramatically improved, while I've simultaneously been pushing it to its boundaries. I'm regularly confronted with issues solved in C++11 or C++14. My skill with templates has increased to the point that last week I used them to write code only possible with templates (I think). The language's warts and wrinkles are slowly becoming second nature to me, all while I try to prevent them from forcing me down ugly roads.
Principals of software design that never took in a scholastic setting are starting to have real impact. A more visceral understanding of decoupling provided by factories, the perils of inheritance etc.
The vital importance of excellent tooling.

I've really been enjoying my time. My team has been fantastic, and our project, [REDACTED], is going quite well.