Comment by tstordyallison

It’s not just straight pickle (usually) - there’s a layer in between that allows at the very least for the handling of deprecated fields/new fields/renames etc.

But - after a change - you have to choose either to leave that ‘backward compatibility’ in-place (essentially forever), or put together a job to run (on that scheduler! Hah) to go re-write in your new format. If you care enough, you might - and then you can remove your logic to handle the old names/shapes.

The charm in a lot of it is in its simplicity. It doesn’t claim to very smart, but people get it - and are often remarkably productive.