[dkersten]

I suppose one needs to take care that migrations are never lossy so that the full information for upgrading or downgrading a version is available.

[tedmiston]

Yeah, that's the challenge. For instance, how do you handle when a column was one data type but then down the road was changed to another type when the two aren't cross compatible or could potentially break?

[raulk]

You could retain this info in a meta field of flexible type. For a DB, it could a JSON type. For messages, it could be an extra _meta field on the message that the systems themselves ignore.