What’s interesting about the definition of a polyglot in the linguistic sense is that it’s someone who “knows and is able to use several languages”. This same definition can be applied to engineering, but it is not limited to programming languages.
Are you a Jack of all trades? Being a well-rounded and versatile software developer is great. Being able to use multiple technologies and programs and many different programming languages can only help your career and can make you a much more valuable software developer than someone who only
knows one specific technology or programming language. But it’s very difficult to market yourself as a jack-of-all-trades.
It’s nice to have a developer who can do anything on the team, but rarely do companies or clients set out to find that kind of person. Even though you may be awesome at all kinds of different technologies and know 50 different programming languages, you still will be better off picking some specialty—even if it changes from time to time.
Learn as much as you can and become as flexible as possible, but also have a specialty that makes you unique and stand out. If you have to choose between the two options, start with specialization and branch out later.