Sure, but nobody is upset if he sees twit 1 min later than someone else, since most of the time you can't even tell, a lot of people would bitch about 1 min latency on chats.
So twitter can afford to deliver those tweets with higher maximum latency than WhatsApp.
And it's scaling when you need to keep low latencies, that really kills you, at least in my experience.
WhatsApp and twitter’s latency calculations are on different things.
Twitter’s latency stems from calculating what tweets should show on a given request. Even if you try to show tweets from 1 minute ago, it’s hard to cache that stuff using traditional systems because of the fan out. If an account with 50 million followers tweets, you need to update 50 million timelines. How do you do that quickly?
And you would have to define maximum latency, is it seconds, minutes, hours? because you can’t have the timelines be inconsistent for too long as that leads to some people getting news faster than others.
now you have to deliver them, exactly one time, to each recipient or groups of recipients, through different network topologies, with different challenges and vastly different bandwidth and latency guarantees, in exact order, while also keeping track of who is online e who's not, and distributing that information in real time, only to the edge nodes that should know about it, all of that fully E2E encrypted but stored (indefinitely?) in case the recipient is currently offline and unless that recipient blocked the sender.
let's agree that both companies solve hard problems and that it's not the technical difficulties that make the two companies sizes so different.
So twitter can afford to deliver those tweets with higher maximum latency than WhatsApp.
And it's scaling when you need to keep low latencies, that really kills you, at least in my experience.