“I think the main takeaway looking at these calculations is that many of these numbers are small numbers on the scale of modern computers!”
Twitter handles about 500 million tweets a day, roughly the same rate as 2013. Two days of hot tweets fit in 503GB of RAM, and the whole follow graph takes 400GB. A Rust prototype handles 35x full timeline load on a handful of cores. Twitter ran a data center fleet and thousands of engineers to serve a dataset that fits in one rack.