I think this is ignoring a lot of prior art. Our deploys at Yelp in roughly 2010 worked this way -- you flagged a branch as ready to land, a system (`pushmaster` aka `pushhamster`) verified that it passed tests and then did an octopus merge of a bunch of branches, verified that that passed tests, deployed it, and then landed the whole thing to master after it was happy on staging. And this wasn't novel at Yelp; we inherited the practice from PayPal, so my guess is that most companies that care at all about release engineering have been doing it this way for decades and it was just a big regression when people stopped having professional release management teams and started just cowboy pushing to `master` / `main` on github some time in the mid 2010's.

> we inherited the practice from PayPal

Paypal got it from eBay, which in 2000's was rolling out 20M LOC worldwide every week or two on "release trains". There, a small team of kernel engineers rotated doing the merging -- two weeks of clearcase hell when it was your turn.

And, since eBay wrote their own developer tools, you'd have to deploy different tooling depending on the branch you were on. But because of their custom tooling, if there was a problem in the UI, in debug mode you could select an element in the browser UI and navigate to the java class in a particular component and branch that produced that element.

That's super interesting, thanks for sharing the Yelp/PayPal lineage. You're right: there's probably a lot of prior art in internal release engineering systems that never got much written up publicly.

The angle we took in the blog post focused on what was widely documented and accessible to the community (open-source tools like Bors, Homu, Bulldozer, Zuul, etc.), because those left a public footprint that other teams could adopt or build on.

It's a great reminder that many companies were solving the "keep main green" problem in parallel (some with pretty sophisticated tooling), even if it didn't make it into OSS or blog posts at the time.