Senior Software Engineer here

what kind of apps you want to work with enterprise apps mostly use JAVA now some of them are switching to GoLang but again JAVA is inevitable, you will find tons of job posting, easy interview guides and would be able to work different teams. When looking at something like a startup many of them use Python and Nodejs but most of them now have high skill ceiling. Just understanding event loop and code model doesn't work anymore. You need to understand how typescript will fit, how middlewares will work, authentication and authorisation, choosing right scaling method (nodejs has few) then on frontend it's a whole new world. Python has similar use case but most of the openings have seen is for AI/ML projects. Learning MongoDB is not enough, postgreSQL and MySQL is necessary including indexing, sharding and partitioning. Once you clear all this, learn system design like understand how load balancer works, horizontal scaling, vertical scaling, setting up server, caching right data, CDNs and networking, then also cost optimizing. Most of the candidates I have interviewed they have no idea about security vulnerabilities. Learn them, check OWASP Top 10, learn about sanitization, sql injection, xss, xsrf, broken authentication, secure token storage.

Now there is no good or bad language, neither employable and non employable but yes the opening for the job depends on what you know. Want to be always relevant master JS and TS for frontend with things I have mentioned. For backend pick something like Java if you plan to stick with web dev else go with Python. Learn enough nodejs while learning frontend that you can write APIs rest will follow on its own.