Build a company around creating a best in class development environment that they can sell to other tech companies. This would involve everything from repository management (on top of git) to build & compilation tooling to automated testing and probably more than that eventually.

Once companies reach a certain scale they inevitably expend some of their resources on building internal development tools. At Foursquare we have 1 person (on a team of ~80) doing this fulltime. Google has spent a ton of effort on this with blaze. Facebook & Twitter have done similar work. But it's all fragmented and it's all reinventing the wheel.

A company should do this right for everyone. If it was good enough I'd happily write very very large checks to use it.

Honestly I think this is what GitHub should be doing, but they don't appear to have their shit together enough to innovate so someone else should do it.