Q: Online Community — How to trigger interaction with users?

I don’t know if this kind of writing is allowed, so I’ll take my chances - Please advise.

I am currently busy with a graduation assignment at a company that is specialised in e-commerce development. I am creating an online community (blog) platform, and I would like to have some opinions on a few matters. I know this can be more of a discussion rather than a story, but I would like to ask it anyway.

The target audience (e-commerce developers familiar with, for example, Magento 2 Framework) will be able to share their knowledge on this platform. This may be in the form of a tutorial, course, tips & tricks, new developments etc. The platform must be a tool to create one giant technical ‘club’ consisting of talented developers all over the world.

My biggest concern is the ability to trigger e-commerce developers to participate in my community and actually share their knowledge, with other similar sources out there like Scotch.io for example.

So my question is:

What will drive people/developers to write a post for an online community platform like Medium, Scotch.io or Stackoverflow? I.e. what do they get out of it?

Link to original post on Stackexchange.