[calderwoodra]

I think this is a little inaccurate. Google's monorepo does have branching but it is a second class citizen with minimal support that most engineers aren't aware of unless you've carried a product through many releases.

That being said, every release can stand on its own and be iteratively changed without taking on changes from the rest of the company.

The highest possibilities for breakages to be introduced are at boundaries where your long running services depend on an another team's service(s), but this problem is not unique to Google.

Google can choose to maintain a long running maintenance project or deprecate it, and I won't claim to know what plays the biggest factor in that decision (it's likely unique to every team), but having a monorepo definitely is not part of the equation.

(Also worked at Google for some time)

Edit: typos

[goodcjw2]

We actually tried that route (i.e. using a branch) before deprecating the project. Instead, the infra team told us something like the branch can only live for about 6 month before they have to deprecate the toolchain that supports the branches that are more than 6 months old.

(edit: typo)