It's much more complicated at scale. Many conflicts can come from things like backporting or working on a feature in a codebase that deals with a lot of churn (

It's much more complicated at scale. Many conflicts can come from things like backporting or working on a feature in a codebase that deals with a lot of churn (like some drivers or the Linux kernel). Some open source projects have internal versions of the code within the company that eventually gets upstreamed after internal validation takes place, but that version of the code may not rebase for a while for some very good reasons (unresolved instability on the main branch, for instance). In that case, the code base is now both significantly ahead (with internal changes) and significantly behind (due to the other changes that have come from other massive organizations working on the same project). I have published on the topic of merge conflicts a couple times, and even I didn't understand how inevitable massive merge conflicts can be until I joined a kernel integration team at a large company. Open source is a helluva drug :)