The question is how your partition your organisation. Classic is something like Development | Testing | Production. DevOps wants to integrate the different department, but you cannot build one huge team of 100 people.

You could partition by product instead Gmail | Search | Maps | etc.

You could do both partitions, which gives you Matrix Management [0]. In the software world this is more commonly known as introducing the role of a product manager in addition to a team manager.

[0] https://en.wikipedia.org/wiki/Matrix_management

Just to clarify, that's how I run it here but I've been told by some fairly respected devops people that it's not really devops. But in general I agree.