I do not find this very interesting, and over the next few years, I want to transition to jobs involving design and implementation at the lower-level of the tech stack, or in other words, I want to work on the (mostly open-source) low-level infrastructure instead of a commercial app. Some recent examples of such low-level work I can think of, are: Linux kernel development, sanitizers and static analysis in GCC and Clang, new languages and their compilers and tools (Rust, Go, WebAssembly, etc), regular improvements in web browser engines, databases features.
I would appreciate any advice on how to transition to this kind of work, given that such jobs are very few in number and require highly specialized knowledge, compared to a generic app developer role.
PS. I am outside the US.