Google's V8 JavaScript engine is written in C++, so learning C++ will help me understand V8 source code.
Node.js is written in C++ and part of its code ecosystem are C++ APIs.
C++ (/ˌsiːˌplʌsˈplʌs/) is a general-purpose programming language created by Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significantly over time, and modern C++ now has object-oriented, generic, and functional features in addition to facilities for low-level memory manipulation. It is almost always implemented as a compiled language, and many vendors provide C++ compilers, including the Free Software Foundation, LLVM, Microsoft, Intel, Oracle, and IBM, so it is available on many platforms. -Wikipedia:
In computer programming, a runtime library is a special program library used by a compiler, to implement functions built into a programming language, during the runtime (execution) of a computer program. This often includes functions for input and output, or for memory management.
A run-time system (also called runtime system or just runtime) is software designed to support the execution of computer programs written in some computer language. The run-time system contains implementations of basic low-level commands and may also implement higher-level commands and may support type checking, debugging, and even code generation and optimization. Some services of the run-time system are accessible to the programmer through an application programming interface, but other services (such as task scheduling and resource management) may be inaccessible.
I got a real practice for tree traversal algorithms, like DFS and BFS for the first time from the syntax trees, using hash tables to resolve identifiers. Learning OOP and design patterns, many structs involves inheritances and we applied the visitor pattern to traverse. Learn assembly languages: the compiler will emit low level code and debugging in a lower level gives coding a different perspective.