> Once it's 100%, delete the old serverless function. I suggest keeping it around for a while. A function not being used should have cost equivalent to a data

> Once it's 100%, delete the old serverless function. I suggest keeping it around for a while. A function not being used should have cost equivalent to a database entry, not a running container or VM, so this should be cheap and the benefits are large. It's still possible to discover you need to roll back a change, even after you've been at 100% for a while. (And no, 'roll forward' is not a sufficient option, especially if that requires coding up a fix you may not even understand yet.)