.NET Core vs Symfony

I'm about to begin working on an API, for which I plan to add GraphQL connectivity for processing data. The data processed will mainly be audio files being downloaded/uploaded with some user messaging & authentication.

I don't mind the difficulty in any service since I've used C++ (for data structures & algorithms at least) and would also say I am patient and can learn fairly quickly. My main concerns would be their performance, libraries/community, and job marketability.

Why I'm stuck between these three...

Symfony: I've programmed in PHP for back-end in a previous internship and may do so again in a few months.

Node.js: It's newer than PHP, and it's JavaScript where my front-end stack will be React and (likely) React Native.

Golang: It's newer than PHP, I've heard of its good performance, and it would be nice to learn a new (growing) language.

There has been a lot of buzz around having PostgreSQL for ASP.NET Core 3.1 web apps. But Configuring Identity Server 4 with PostgreSQL is a real challenge. I've made a simple video to configure the ASP.NET Core 3.1 based Web application that uses AngualrJS as front end with Single Page App capabilities with Identity Server 4 talking to the PostgreSQL database. Check out this Video tutorial on how to do that in detail http://bit.ly/2EkotL5 You can access the entire code here on github http://bit.ly/35okpFj

I was researching multiple high performance, concurent//parallel languages for the needs of authentication and authorization server, to be built on microservice architecture and Linux OS. Node.js with its asynchronous behavior and event loop suits the case best. Python Django & Flash turns to be slower and .NET Core & Framework wasn't the best choice for the Linux environment at the time (summer 2018).

I also tested Go lang and Rust, although they didn't meet the quick prototyping criteria as both languages are young and lacking libraries or battle-tested ORM.