I've always thought mice type SLAs were stupid. Big companies use them to avoid every potential lawsuit or to deliberately screw consumers over. Decent & good small companies use them to deal with every bad experience and to come across as "professional." I've gotten burned on more written contracts than the rare judgment mistake I've made in character or client/vendor relationship compatibility where we did business on a handshake. Written contracts are good only for the purpose of making sure that one party doesn't honestly forget what was agreed to. A relationship can sour over an honest mistake either side could. Once the lawyers get involved nobody wins.
The spirit of the deal is the most important starting point to me. Even when both parties have good intentions (the spirit of the deal), successful relationships are challenging. Writing code is far easier for me than navigating the business end of things. I end up reading articles like this when trying to fix something both parties couldn't have anticipated and still come up short for the right solution when I discover I was already tuned in to nuances many people overlook.
https://hbr.org/2003/02/negotiating-the-spirit-of-the-deal
