The consequence of a bad deploy can be millions of dollars for a client or business. Depending on the industry, it can be a million dollars in the course of an

The consequence of a bad deploy can be millions of dollars for a client or business. Depending on the industry, it can be a million dollars in the course of an hour. If a dev team works Monday to Friday, then it's likely they're going to be harder to reach and coordinate with during the weekend. It usually costs less money to wait an additional business day than to get a team of engineers in on a weekend to try and fix a problem in production. If a roof leaks on a Sunday and the roofer doesn't work Sundays it's going to be similarly difficult to get the roofer to come and fix it. The difference is the order of magnitude of money lost for a leaky roof vs a software fuckup at a pharma company or a business conglomerate. It's ultimately the responsibility of the developers to test their code sufficiently so that there never is a weekend problem to begin with, but the reality is there will always be bugs that crop up in production, and you can only control that so much. You can usually control deploying on a Friday though.