Which parallel development to choose for a mobile developer?

Question

Career in IT

Hello! He started his career in IT as a "webmaster" (layout, jQuery, some PHP, stretching the layout on Wordpress). After that, he went into JavaScript development (React.JS, Node.js (Express)) and then more on tutorials and videos from the how to genre, without delving into the language and platform.
For the last two and a half years I have been doing only iOS development (Swift) and I don’t plan to leave this direction anywhere in the future, but I want to start studying and developing in the backend (for general education and improving skills, except for iOS, you can say to become a Fullstack mobile developer :) ). Can't decide which technologies and platforms to choose? Now I read JS in my free time, but the JavaScript language itself after Swift is perceived very hard (weak typing, strange OOP, etc.). Server Side Swift (VAPOR and the like) would not be very desirable (I did not find any vacancies and demand in Swift on the back and the community is not very large, compared to the same JS / TS). I would love to hear your opinions and advice!

PS Offtopic question :) I would also like to clarify whether it is possible / worth it to skip JS and start learning TypeScript right away? Or is there nothing to do without understanding JS in TS? :)

Answer 1

If for general education, then any, but preferably more or less popular.
If in terms of demand and the number of vacancies - Python and JS seem to be the top 2 among languages.
If it is important to have typing and canonical OOP - Java or C # (ASP.NET). And there are plenty of vacancies.

Answer 2

Java, Kotlin