It takes engineers to run and utilize all that stuff. You don't need a back-end scaling team you're only throwing around XMPP in Erlang. Edit: I know b/c I've

It takes engineers to run and utilize all that stuff. You don't need a back-end scaling team you're only throwing around XMPP in Erlang. Edit: I know b/c I've done that before in $previousjob. Storage is hard. Storage is where the money goes. Durability is expensive. Storing ephemeral stuff in a non-durable KV store is easy, cheap, and trivial to scale. This is why WhatsApp didn't have so many people, not because they were geniuses.