Before bring acquired, WhatsApp had what, 30 employees?
How did they do it? I know they used custom BSD servers so that a single box could keep close to 1M TCP connections open. I'm sure with a fixed target to aim for and all scope known upfront a small crack team of devs could do something similar for Twitter.
One-to-one vs. many-to-many messaging. The amount of work you need to do to deliver a WhatsApp message is constant and small -- just route the message to a single recipient's mailbox. The amount of work Twitter has to do to deliver a message grows as a function of followers. One celebrity tweeting another celebrity means you have to deliver the message to the mailboxes of the followers of both -- millions of times more work than WhatsApp per message. In addition, Twitter persists all the messages while WhatsApp doesn't.
This! Everyone keep's saying it's BSD Erlang and jumping on the Erlang train. Fine tools btw, but WhatsApp is super simple compared to Twitter. rolls eyes
How did they do it? I know they used custom BSD servers so that a single box could keep close to 1M TCP connections open. I'm sure with a fixed target to aim for and all scope known upfront a small crack team of devs could do something similar for Twitter.