This might be me being exceedingly charitable to the OP, but I see his point differently: There's a ton of work involved in making a platform like WhatsApp a p

This might be me being exceedingly charitable to the OP, but I see his point differently: There's a ton of work involved in making a platform like WhatsApp a polished user experience. There's then a ton more work involved in making it _solid_. In choosing Erlang, they chose a platform that trivialises a large part (though not all) of the latter, allowing them to focus on the former.