[mrep]

If they were deploying to their entire fleet all at the same time, I would also shiver.

However, most likely that have many stages in their deployment with testing and monitoring that exponentially deploys and if any of those stages don't pass, they auto-rollback.

The End game: minimizing risk with code changes.

1. Deploying more often allows easier root cause analysis to identify the code breaking change.

2. exponential deployment allows developers to monitor their services as it partakes in more variation (more users = greater chance of edge case breaking bug)

3. proper monitoring and test coverage while using auto-rollbacks allows developers to deploy without fear as any unintended effects will be detected at the soonest possible moment while minimizing cost to the users of that breaking change. Then, auto-rollbacks will redeploy code changes that previously worked which should automatically mitigate that code breaking change.