I've had one co-worker with something like a decade of experience on paper, who was proud of his C++ despite having never heard of the standard template library — lots of `new` and `free`, not a single smart pointer (https://en.cppreference.com/w/cpp/memory#Smart_pointers). And the code they wrote had a lot of copy-paste going on, which I ended up finding because I'd put in a "TODO: deduplicate this" comment somewhere and found it in his newly duplicated class one day.

They absolutely were not interested in learning anything. I left knowing more C++ than they did despite having started there with total C++ experience of a hello world tutorial, and the fact that I still don't count myself as a C++ dev today.

To be fair when a company says they use C++, it can mean anything from "C with classes" to crazy metaprogramming with almost automatic memory management. Since they have over 10 years experience, they are almost definitely in the former camp.

I would never utter the phrase "I know C++" because it can mean so many different things to so many different people, and I don't think anyone truly knows the whole language.

Not using templates nor smart pointers doesn't sound that bad to me(unless the entirety/majority of the codebase was written with them in mind), the duplication thing is more questionable.

Tbh, I also (sort of) knew C++, studied in school and a few semesters worth in college (CUDA, DSA, Computer vision elective,compiler design) but I still don't know STL. (I had been then interviewing using Java and Python.)