Strong principles

WhatsApp designs and builds its product with specific principles in mind. These principles are at the core of the decision-making process. Here are some examples of these shared values:

• The interface should feel native to the device the person is using
• The app should be lightweight and require as little storage as possible
• The interface should be simple
• User actions and animations should be quick to respond
• Features should provide obvious utility so they require little introduction

• At Facebook, you start with a problem. Then you propose a solution. If that gets the team excited, you test it. If it tests well, you start to build it and you take it out for a small test to see if it solves the problem. If it solves the problem well, you build it out to have a rich feature...