How to build a community platform?

Hi guys,

I've been more and more interested in building a community for certain subjects and industries. Are there any frameworks or templates I should be looking at? I'm a designer looking to hire a developer to build this community. I was hoping we wouldn't have to build it from scratch and use frameworks to cut down costs. My vision of a community would be like Hashnode of course, Reddit, etc. Where users can sign up, upload content and other users can interact via commenting, liking etc. Any help would be appreciated!