Hacker News 上看到「Reformatting 100k Files at Google in 2011 (le-brun.eu)」這篇，原文在「The Story of Reformatting 100k Files at Google in 2012」這邊。
這篇除了作者寫的東西以外，Russ Cox 也在 Hacker News 上面分享了一些當時的背景。
故事是 2012 年的時候，作者 Laurent Le Brun (LinkedIn) 在德國，剛加入 Google 沒多久，負責處理 Google 內部的編譯工具 Blaze (外部稱 Bazel)：
Back in September 2012, I was a junior engineer at Google, working on Bazel (Google’s build tool, also known internally as Blaze).
然後他與他的 team lead 收到美國團隊兩位工程師的會議邀請：
One day, a mysterious calendar invite landed in my inbox. It was sent by two engineers in the US, and I was invited along with my team lead.
然後這兩位是 Rob Pike 以及 Russ Cox：
I quickly recognized the names: Rob Pike and Russ Cox. Though I hadn't worked with them, I knew them by reputation: Russ Cox because I enjoyed reading his blog posts, and Rob Pike because, well… he’s famous.
作者這邊也懶得介紹 Rob Pike 了，畢竟是當年 Bell Labs 的 Plan 9 的頭頭，然後又是 UTF-8 的發明人，後來在 Google 裡面也是 Go (程式語言) 的頭頭... 順便一提 Go 的吉祥物是他老婆畫的。
他們兩個人希望把全公司所有的 BUILD 檔案格式統一：
During the meeting, Rob and Russ shared their ambitious plan: to reformat every single Bazel BUILD file in Google’s codebase and enforce this formatting with a presubmit script.
中間有提到一些工程上的進行方式，但對我來說比較重要的是這幾個，首先是 Russ Cox 提到他在 Go 的團隊裡面學到的，(在大公司裡面) 不要讓工程師浪費時間在 formatting 之類的問題：
The formatting issue is a problem that should not exist and that we care enough about to spend our own engineering time eliminating it. I understand that it does not seem a priori that automated formatting would make a significant difference. I didn't truly understand it myself until we eliminated it from the Go code review and code editing processes. Hopefully in six months or a year, when everything is converted and we look back at this, the benefits will be clearer in retrospect.
另外在 update 的地方作者也提到了當時決定一次到位，把所有的 BUILD 檔案都修正完，而不是讓後續的人在更新時才強制要求，這樣可以避免後面的人接手的時候產生大量的 diff 而導致 review 困難：
Why not enable the new formatter without updating all the files? This would lead to long diffs whenever someone modifies a file, making the change hard to review. The cost would be spread over all the engineers in the company.