[aledalgrande]

My point is that if there is any downtime for the switch, for example restarting a service, it's not atomic. A small percentage of failed requests can still be high in absolute terms for a company like Slack, so why not using a paradigm [1] where you have atomic switch? And also instant rollback.

[1] https://www.martinfowler.com/bliki/BlueGreenDeployment.html

[lukevp]

Nginx can hot reload a config file while running that’s pointed at a different directory, or perhaps they’re updating a symlink?

[aledalgrande]

Possible!