I think some clarification is required in terms of what role Discourse would play here.
How does your use case relate to discussion/conversation. What would be done on discourse and what would be done on your server.
This is a broad statement. Discourse in itself is a whole system. What data would you show on Discourse which comes from or is synced with your other server.
From the information you’ve shared, it could be done via a plugin for sure. There are integrations for WordPress, GitHub, etc which might be doing a similar thing what you’re trying to do. But that’s me trying to read between the lines.
If you want to understand how to build plugins, here’s a great collection of links by @merefield
This is also a good one.