For a newcomer, I think you have a very solid grasp of how to get going. From a raw users standpoint I don’t think you’ll run into any streaming issues at all. Keep in mind the whole elixir package management system ran for a very long time on a single 512mb server. Your ECS + Docker idea sounds like a fine idea, but you could probably get away with simpler depending on whether ECS is something you are familiar with or not.

Live streaming and video work however is an area I know less about, so perhaps someone else can weigh in on that. I’m going to add a membrane tag to the post to see if we can help.

From a code management / maintenance standpoint I definitely think you have the right idea with a phoenix mono repo.

Hi @chris-menz welcome! This is a potentially very large topic, but let me kick it off by providing some answers that I think reflect community norms, lay out the assumptions underlying those norms, and then you can see what may be different in your case.

Simple answers: A single Elixir application that has Phoenix for UI / chat / REST API, Oban for background jobs and postgres as your database would be the recommend place to start.

So, you haven’t actually talked about any scale, so it’s hard to say. But what can be said is that efficient use of Postgres, fronted by Phoenix, will easiliy scale to tends or even hundreds of thousands of concurrent users on a single server.

I would make a choice about separate services depending more on your team and the size of the team than the technologies. If you have just 1 small team, starting with separate services is likely to introduce a lot of complexity, because the boundaries between those services is unlikely to be very clear at the start, and the cost of refactoring is much higher. Deployment becomes significantly more complicated as well.

The way you are framing this is good. Building this to be the scale of youtube at the start is going to be super complex, and you can cross that bridge when you come to it. At the start simplicity is very important so that you can iterate quickly, and you just want to make sure the scaling will be good enough that it won’t cause issues prematurely. A traditional Phoenix app is pretty well tuned to give you what you want here.

To provide anything more concrete though you’d need to be more concrete about what you expect the application to need to do.

Then you can follow Phoenix’s tutorials and you’re already covered. A brand new app with zero optimizations and no caching will handle even 10k concurrent users just fine.

Though depending on database usage I’d tune some of your Ecto.Repo parameters e.g. queue_target can be a higher value (say 5000ms) so nobody gets the “request timed out” page even in loaded conditions.

And that still wouldn’t be on Elixir, it’d be your DB being the bottleneck.