> Do you really run an operation where you have soldered together all of your servers, created a data center inside your headquarters, within which you run all of your mission critical CI/testing/deployment services? Because unless you're one of a handful of tech companies,

The contrary. You represent the handful that didn't, and the "handful" of tech companies you suggest is much larger than you think.

Based on this comment and the recent reply in this thread I can tell you've mostly worked with small-scale architectures. Third party tooling and workflows do make a lot of sense at a small scale, but the point at which you outgrow those solutions comes a lot sooner than you think. When I arrived at Foursquare the entire operation was on Amazon; when I left a year and a half later, much of it was on physical equipment. And Foursquare is not a Google-scale operation -- virtualization and customer cotenancy just have a serious impact on SLA that is less pronounced at smaller scales.

It's easy to think your experiences represent the industry, as your comments suggest. It's also easy to think HN represents the industry, where startups reign supreme and everybody loves working Lean Devops. The fact is, neither of those statements are accurate, and beyond a six (or maybe seven) figure architecture you start having a harder time justifying third parties financially and operationally.

I do use Amazon currently, just as an off-site backup for on-site monitoring that I've built. That's common.