Within Facebook, anyone can look at and change the code in its source repositories. The facebook.com site has its code updated twice daily, he said, so the barrier to getting new code in the hands of users is low. Those changes can be fixes or new features.
As an example, he noted that the “Look Back” videos, which were created by Facebook for each user and reviewed all of their posts to the service, added a huge amount of data and required a lot more network bandwidth. The process of creating and serving all of those videos was the topic of a Facebook engineering blog post. In all 720 million videos were created, which required an additional 11 petabytes of storage, as well as consuming 450 Gb/second of peak network bandwidth for people viewing the videos. The Look Back feature was conceived, provisioned, and deployed in only 30 days, he said.