If you think they don't have a good engineering culture, you should check out their open-sourced tools[0].

I had an opportunity to work with some of their open-sourced tools (Airflow was one of them) about 5 years ago at my old workplace, and the quality of their product and documentation is nothing but superb.

At my current workplace, I use Enzyme all the time when dealing with unit tests, and it seems to be pretty much the industry standard for React UI unit-testing.

0. https://airbnb.io/projects/

There's a great deal of recommendations, fraud detection, global payment complexity, etc. behind the CRUD app.

For a Linux user, you can already build such a system yourself quite trivially by getting an FTP account, mounting it locally with curlftpfs, and then using SVN or CVS on the mounted filesystem. From Windows or Mac, this FTP account could be accessed through built-in software.

Facebook is also a CRUD app. What's your point?