I worked at AWS. Each team/service had their own alpha/beta/delta/gamma development environments, as well as one-box and blue/green production deployment envir

I worked at AWS. Each team/service had their own alpha/beta/delta/gamma development environments, as well as one-box and blue/green production deployment environments, and deployed to waves of regions from smaller groups at the start to bigger groups at the end. That all seemed to work reasonably well.