What other fields should I pick up along the way? And, do I need to have significant knowledge of AI/ML/Cloud-computing/Data-Science, etc. to sustain myself in the long-run (long-run being defined as 15 years)
That said, if I had to choose a couple of languages for the rest of my career I would choose C, C++, and SQL. All of those have enjoyed huge success since they were introduced, with mountains of legacy code and plenty of new development.
Once you master C and C++ a lot of similar languages should be very easy to learn: Java, C#, Python, Go, Ruby, PHP, Swift... they are all more alike than not.
As a hiring manager I would not be very interested in someone who only worked in one or two languages, or only had language expertise to offer. A candidate stuck with two languages for years would send the wrong message for sure.
To build and sustain a long career you need to solve problems and add value. You need to get along with people and contribute positively to a team. You need to learn business domains, not just languages and tools. You need to be the person who says “I can figure it out,” not the person who says “Leave me alone, I only want to write C++ code.”
While this is a plug, I genuinely believe joining the event and talking to them would help you. The networking / hallway effect, even virtually, shouldn't be underestimated either.
Good luck -- there's definitely lots of system software people needed, as someone else here pointed out.
On the Problem Domain front, Cloud Computing and Data Science are here to stay. They are fundamental shifts in the computing space and hence one needs to become knowledgeable in them. I am not too gung-ho on the AI/ML fad since there is too much hype around its supposed benefits but of course you can study it for its intellectual challenge and apply as need arises.
In the first few lectures he lays out what he thinks it takes to be a great programmer. I’m pretty confident that there will be a job market for great programmers for at least the next 15 years.
They are hard to replace, are tough problem solvers and deliver code in our toughest environments.
I think all this data/ai focus is nice, but I think hardware is the real deal breaker. Have an eye on Rust in all the regards.
- C as a workaround for a Docker problem.
- C++ with C# in Unity.
- C++ in Android with Kotlin
As you hinted in the question, it is good to combine C++ with other skills.
If you want to stay purely in C++, then the automotive and aeronautical industries are heavy C++ users.
But as @gregjor says its best not to stick to one language. To add to that, I would recommend not to define yourself by the language you program in and instead be prepared to stay flexible and keep learning.
Regardless of what I think about C, it is undoubtly the king of UNIX/POSIX platforms and embedded development. So that might be an area you feel at home with.
Although C++ has lost the full stack role it once enjoyed with the 90's OS stacks, it is the current king of GPGPU programming (CUDA, Metal Shaders, SYCL and HLSL), HFT, what game engines use at their core.
Finally as many are pointing out, don't silo yourself with one language, most of use many languages at once.
For example using C++ alongside either Java or .NET is quite common.
C is mostly used these days for embedded systems. C++ for high performance network services. Higher level and more sophisticated languages are coming for those domains, e.g. Rust. Lua is interesting for embedded systems, and the Erlang VM for network services.
FWIW, I am on year 16 of my own C/C++ only career.
EDIT: Huh I’m old