At Facebook, you start with a problem. Then you propose a solution to that problem. If that gets the team excited, you test it in research. 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 set and release to a wider audience. The process is iterative and it has a lot of checks and balances naturally built in. It’s a mature process and it works well.