Deployment plans & team should be part of initial technical planning. They are the linchpin to ensuring happy customers. No?

The move from labor-intensive, big-bang, monolithic deployments to fully automated, tested, non-event deployments has been a bigger positive change for me than any defined methodology or specific technology.

Continuous testing/building is a major component to a good project. I know it'd been done for years by some groups Agile became a Thing.

I tried to track the history of CI once[1] -- a similar practice may date back as far as the 60s at IBM. There are multiple sources indicating daily builds with tests at Microsoft from at least the early 90s (not quite CI but at the scale of the projects probably as close as practical at the time). Long before Agile became trendy in the 00's.

[1]: http://www.alittlemadness.com/2009/01/09/continuous-integrat...