Curious to know how many people do zero-downtime deployment of backend code and how many people regularly take their service down, even if very briefly, to roll out new code.
Zero-downtime deployment is valuable in some applications and a complete waste of effort in others, of course, but that doesn’t mean people do it when they should and skip it when it’s not useful.
Very rarely. Most of our services are ECS which will manage rolling deployments. Older/legacy systems are manually taken out of load balancer, upgraded then added back.
Only times I can think of have been backwards incompatible database changes/database engine upgrades. This is rare.