Does it store data persistently anywhere (on servers?). If so where?

It looks like it stores it on Jazz Flex, a paid service.

Free tier is 1GB of storage, and it goes up from there.

The Jazz Mesh stores everything you sync through it in geographically distributed and redundant servers (with backups to S3)

That sounds a lot more promising!

Which brings in even more questions. What is the performance of these multiplayer experiences? Can I have 1000+ users all connected to the same chat session? What about 10,000?

(these numbers might seem high, but they're what I'm expected to deliver in my day-job)

Eventually, yes! The origin story of Jazz is that I did a lot of experiments and research to convince myself of satisfying performance characteristics. Right now, the pure-TypeScript implementation is not very optimised and I'm very intentionally optimising it as needed for early adopter apps instead of predicting where bottlenecks are. So if you start building a chat app with 10s of thousands of users interacting, we'll make sure that's possible by when you want to launch.

This lets us more easily prioritise features vs performance.

this is amazing, keep up the great work. been wanting something like this forever

Not to go off topic but isn't performance metrics your responsibility ? Those are small numbers in reality, but if you are not performing your own tests and trusting the maintainer/publisher instead then you're not doing your 'day-job' properly.

Yeah, I hear you. Which is why we assessed and designed our own platform for handling the above stated traffic (and much more) for multi-user real-time chat sessions.

The commenter seems to know a lot about Jazz, so I took the opportunity to ask further questions.

I made Jazz, that's why I know a lot about it ;) (I now have people helping me)

Let me know if you'd like to know anything else.

I like the idea, I have some implementation questions but I’ll catch you on GitHub. Nice work so far though.

Good stuff, and I hope I didn’t come across too rude but 10k parallel is not a problem for even basic setups to manage, it’s a problem solved many different ways some out of the box some not. Maybe your question was phrased wrong. But hit into 10kk parallel, there’s an interesting metric to discuss optimization.

I’m reminded of the quasi meme “You have designed an infinitely scalable service for 10 clients “

10k parallel users I agree, but 10k receiving all updates from the other 9999 and vice versa can become quite a complex problem to solve.

Especially within time (latency), monetary hosting cost, and accuracy constraints.

For example, an MMO town with 10,000 connected clients all viewing the same complex session state of all other users and entities in one town.

That’s a lot of room for error. Or am I missing something?

That scenario is complex to me and has remained complex to me despite my various times building it out for various products.

What plans do you have for a third-party audit/review of your backend to verify the claims being made?

Its one thing to use this service on the basis of encryption claims - its another thing to have to clean up the mess from a forgotten API key being leaked somewhere... is there, therefore, a third party involved in an audit of Jazz?

First it's all open source so even without knowing that my paid service uses the same open source libraries, you can verify yourself that nothing leaves the client unencrypted.

Of course we will also do public audit(s) with security companies to make sure our cryptographic protocols are sound and implemented correctly.

Thanks for the info. Of course, "its all open source" is a fair answer, but its also a dangerous one, since it shifts culpability for verification to anyone who has the time/resources to audit the open source components that you're using.

But, it also has to be stated, there is no guarantee that you're using only the open source components you've declared, which is why an impartial audit by a third party would be necessary before this project can be used to build products in some industries.

Anyway, I see that you have other concerns, so no worries and thanks for the honest answer.

Just making sure that you saw the point where we will do an impartial third party audit!

I did, and I hope you will promote that fact a bit more overtly, because its kind of important for some .. especially in Europe ..