Congrats with your Python achievement and wish a lot of success with the next one, JSON.
You mentioned you tried C++. I have not idea if this is gonna be a language used too much in the future, but ANSI C, C+ and later on C++ is used for many business-critical services which require reliability, stability and scalability at its heart. The internet companies may use different ways to create such business-critical services these days. When going into microservices, C++ may not be the default language, I don't know. I suggest to check what is used and what will be used in microservices design.