I've asked aws in the past for an API that lets you describe a sequence of changes in a batch, it tells you whether there's any problems with the sequence (like

I've asked aws in the past for an API that lets you describe a sequence of changes in a batch, it tells you whether there's any problems with the sequence (like "at step nine of this batch, you tried to create an instance in a vpc subnet that was deleted by step four of this batch"). And then if there are no issues with the batch, another API lets you have aws execute the batch. It sounds a lot like the DDL transactions you mentioned.