Software Development Trends of the Past Decade
blog.arctype.com"[Javascript] has dramatically improved developer productivity by allowing developers to write both client-side software and backend services in the same language."
I see this mentioned a lot as a theoretical advantage, but I don't really see this happening much. It doesn't take that much to switch between, say, Javascript and Python, or Ruby, or PHP, or whatever. Most web scripting languages are, sure, different than Javascript, but it's not like the difference in switching to SQL or R or CSS or something. I don't really see, in either myself or others I've worked with, much of a bonus from using the same language for client and server side.
Agreed that user-written isomorphic JS is probably overrated, but sharing libraries and tooling across client/server is definitely a huge productivity booster for the ecosystem.
Context and tool switching which can sometimes lower productivity of done often actually does happen. When using JS for both client side and server side it doesn't. From a position of having done both several times in the past years I can tell you it does help
I also think it is easier to get started with as onboarding is much simpler as the base language is the same. Going from Android to iOS development was much harder than going to JS to backend development with NodeJS