What he says here is so true, and something I see many engineers get wrong. Don't glorify and build your career around a single language or methodology. I believe an engineer should learn to build things in the most pragmatic way possible using the best tool for the job. This requires breadth of experience across many areas, and a focus on delivery. The idea of "Java engineer", "Scala engineer", "Golang engineer", et…
I find the idea of being an expert in a language acceptable if it's been used for long enough. Almost all of my coworkers only know .NET and there are enough jobs needing people for new projects and legacy projects that they most likely won't have to learn anything else.
> or tool y
This is where the absurdity begins for me. I have a coworker who is 5 years into his career with the title of "senior react engineer". He started as a "junior react engineer" and at this point only knows how to solve problems with React. He has limited knowledge of the underlying language or general CS concepts. Every problem he encounters can and will be solved by installing NPM packages.