*For you. I think it's a obvious and great advice, software engineers shouldn't define themselves by their stack (Java programmer?).
> They'll have an even more difficult time finding a job if they decide to switch stacks now.
That's why planning your career on changing stacks is such a good advice: you do it before you really need. I have kept a main stack and a "side project" stack for my whole career, going from PHP, ASP, .NET, RoR, clojure, Python then JavaScript for the longest with Rust currently as the side stack I'm learning. Had I got stuck on PHP I would regret it badly.
The language, the stack, etc.. are just details. Given a problem - they can tackle it.
Is it sufficient to be skilled in one programming language, such as Python, and implementing a software renderer or ray tracer, your own neural network, your own HTTPS server, your own OS, your own memory allocator, your own interpreter, your own virtual machine...?
> The language, the stack, etc.. are just details. Given a problem - they can tackle it.
I agree, but are HR people agreeing on this?
Really depends on the company I guess
> Is it sufficient to be skilled in one programming language, such as Python, and implementing a software renderer or ray tracer, your own neural network, your own HTTPS server, your own OS, your own memory allocator, your own interpreter, your own virtual machine...?
May be misunderstanding here, but if I was implementing my own OS I probably wouldn't be using Python. Different problems warrant different solutions – by a "general problem solver" I mean that you think about the coding language as a tool to solve a problem. Similar to how you might think of S3 or ECS as a tool.
That you're thinking of the problem in the business context rather than purely the technical context.
And therein lies the problem. One tech stack won't last your entire career, no matter what it is. You don't need to know everything, but you do need to modernize your skills once a decade or so. Sounds like you are at that point. If you aren't finding Java jobs... pick up a new stack. And 10 years from now, you'll need to do it again.
Staying in this industry for 30/40/50 years is not the same as staying in it for 12. You'll not only have different chapters, you'll have entirely different books. Go start your next one.