You're taking the question very literally. Implicit in it is should I learn Java...

inglor · on July 13, 2018

It's implicit - but my criticism here is mostly that once you know one development stack learning others is significantly easier.

Learning Java is something that a backend developer can likely do in a week - and so is learning Node.js after knowing Java.

ctvo · on July 13, 2018

Knowledge of a language is a scale and not a binary yes / no question.

Being passingly familiar with a language is a week exercise, putting it on your resume / CV and saying you're ready to write production quality code is different.

For Java specifically:

- How does the JVM memory model and other internals work?

- How comfortable am I with the standard library?

- What are the idioms and design patterns used by professionals in Java?

- Performance pitfalls that are tribal knowledge with concurrency / threading, etc?

If the scale of language knowledge is 0-10, getting to 3, where you're familiar with the syntax, common language features and a few APIs is a week's exercise after you've used a few languages (in the same family -- I'm not going to be passingly familiar with Haskell in a week).