[michaelt]

> But why risk it?

I once worked on a system that, when it updated a database row, wrote the software version into a last-modified-by column.

Version 1.23-PRODUCTION worked fine.

Version 1.23.1-SIT worked fine too, in the integration test environment.

Version 1.23.1-PRODUCTION exceeded the column length limit, so it couldn't update any rows. It was completely broken.

If your site has loads of traffic you can just YOLO things from SIT into production and rely on alerting and complaints to catch such issues. But if it's absolutely critical, like a big high profile product launch? I wouldn't want to rely on luck.