Is there a tech blog of how Pix is built?
Things like: counters, news feeds, chat messages, etc
The cost of delivery for doing these things well with a LSM based DB or RDB might actually be higher than Redis. Meaning: you would need more CPUs/memory to deliver this functionality, at scale, than you would with Redis, because of all the overhead of the underlying DB engine.
But for 99% of places that aren’t FAANG, that is fine actually. Anything under like 10k QPS and you can do it in MySQL in the dumbest way possible and no one would ever notice.
I assume most organizations, both small and large, just host on whatever provider they know or that costs them the least. If you have budget maybe you deploy to multiple providers for redundancy? But that increases cost and complexity.
Who’s going to bother with colo given the cost / complexity? Who’s going to run a server from their office given ISP restrictions and downtime fears?
What is the realistic antidote here?