While generally not recommended, there are a few situations where a shared database might be acceptable for microservices.

Everyone says to keep databases separate for each microservice. It helps with deploying and scaling them independently, which is nice. But sometimes, especially when data overlaps a lot or transactions hit a few 'services' that are really just looking at the same info, sharing a database just feels a whole lot easier. I'm really curious about actual situations where engineers made a shared database work well (or totally blew up). What kind of architectural rules did you put in place to avoid the usual headaches, you know, like things getting too tangled or schema problems? What practical upsides and downsides have you actually seen?