It takes engineers to run and utilize all that stuff. You don&#x27;t need a back-end scaling team you&#x27;re only throwing around XMPP in Erlang.<p>Edit: I know b&#x2F;c I&#x27;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&#x27;t have so many people, not because they were geniuses.