10 years back, around 2012-13, Twitter was growing exponentially and serving 150 million users.
They were handling around 6000 tweets/second from these users. I would say, this is still manageable. We have databases with high throughput and write speeds that can handle it.
But the issue occurs for users reading the tweets. Every user queries the home page of Twitter and they have to be served the combination of tweets from everyone they follow. This comes out to be 300k requests/second!!
That’s an insane amount of reads to directly do from the DB!
So how did they solve their scaling issues? Find out in this week's Software Engineering Weekly's issue!