Literally the next sentence: """Similarly, the number of critical issues arising from mobile releases is almost constant regardless of the number of deployments

Literally the next sentence: """Similarly, the number of critical issues arising from mobile releases is almost constant regardless of the number of deployments, indicating that our code quality does not suffer as we continue to scale.""" This is 'productivity' in the sense of the release eng team attempting to measure the volume of code changes they're pushing out and whether changes they made to the push/release process impacted other teams' ability to iterate. Unless you have some insight as to why adopting a more continuous deployment process would change the ratio between LOC pushed or code-changing-diffs pushed to features-or-bugs specifically at Facebook such that they would not function as acceptable proxies, questioning the metric chosen seems hollow. It's certainly not 'productivity' in the sense of whether people on product teams are considered to have done a good job or are deserving of bonuses / promotions.