The WhatsApp Architecture Facebook Bought For $19 Billion

 To start with lets have some facts about watsapp :

• 450 million active users, and reached that number faster than any other company in history.
• 32 engineers, one developer supports 14 million active users.
• 50 billion messages every day across seven platforms (inbound + outbound).
• 1+ million people sign up every day.
• $0 invested in advertising.
• 35% is how much of Facebook's cash is being used for the deal.

• Hundreds of nodes.
• >8000 cores.
• Hundreds of terabytes of RAM.
• >70M Erlang messages per second.
  
  
   As a programmer if you ask me if WhatsApp is worth that much I’ll answer expletive no! It’s just sending stuff over a network. Get real. But I’m also the guy that thought we don’t need blogging platforms because how hard is it to remote login to your own server, edit the index.html file with vi, then write your post in HTML? It has taken quite a while for me to realize it’s not the code stupid, it’s getting all those users to love and use your product that is the hard part. You can’t buy love.
  
  
  What is it that makes WhatsApp so valuable? The technology? Ignore all those people who say they could write WhatsApp in a week with PHP. That’s simply not true. It is as we’ll see pretty cool technology. But certainly Facebook has sufficient chops to build WhatsApp if they wished.
  Let’s look at features. We know WhatsApp is a no gimmicks (no ads, no gimmicks, no games) product with loyal users from across the world. It offers free texting in a cruel world where SMS charges can be abusive. As a sheltered Delhiite has surprised me the most to see how many real people use WhatsApp to really stay in touch with family and friends. So when you get on WhatsApp it’s likely people you know are already on it, since everyone has a phone, which mitigates the empty social network problem. It is aggressively cross platform so everyone you know can use it and it will just work. It “just works” is a phrase often used. It is full featured (shared locations, video, audio, pictures, push-to-talk, voice-messages and photos, read receipt, group-chats, send messages via WiFi, and all can be done regardless of whether the recipient is online or not). It handles the display of native languages well. And using your cell number as identity and your contacts list as a social graph is diabolically simple. There’s no email verification, username and password, and no credit card number required. So it just works.
  
  
  So messaging is a threat to Google and Facebook. The desktop is dead. The web is dying. Messaging + mobile is an entire ecosystem that sidesteps their channel.
  
  
  With the move to mobile we are seeing deportalization of Facebook. The desktop web interface for Facebook is a portal style interface providing access to all the features made available by the backend. It’s big, complicated, and creaky. Who really loves the Facebook UI?
  When Facebook moved to mobile they tried the portal approach and it didn’t work. So they are going with a strategy of smaller, more focussed,purpose built apps. Mobile first! There’s only so much you can do on a small screen. On mobile it’s easier to go find a special app than it is to find a menu buried deep within a complicated portal style application.
  But Facebook is going one step further. They are not only creating purpose built apps, they are providing multiple competing apps that provide similar functionality and these apps may not even share a backend infrastructure. We see this with Messenger and WhatsApp, Instagram and Facebook’s photo app. Paper is an alternate interface to Facebook that provides very limited functionality, but it does what it does very well.
   So to conclude frankly its just facebook who actually sees its future in buying watsapp to conquer the mobile!!!!