[jFriedensreich]

This is perfect example for my remark. With HTTP/2 and SSE you use the exact same feature of your framework to have server side state that would solve this between requests or in any other situation, there is no new problem to solve! Apart from that fact, server side per connection state is usually an anti-pattern, not a common situation as you put it. As far as i can think right now, the only situations where this is required and cannot be solved with better caching would be the same bi directional high frequency streaming situations already mentioned.

[pixel_tracing]

So then how would you solve it without state? For someone like me who is new to the reading these comments I hear a lot of bickering / arguments but no provided solution

[jFriedensreich]

Depends what "IT" is. If you give me one or a few examples what you want to solve I am happy to give more concrete feedback.