Possibly an obvious comment, but reading your post it struck me that any way you slice it, you're more or less building a garbage-collection system, with all th

Possibly an obvious comment, but reading your post it struck me that any way you slice it, you're more or less building a garbage-collection system, with all the various tradeoffs those entail. Different performance issues since it's S3 buckets rather than RAM, but still very dependent on who has references to what, and when you check for it. Your two examples sound to me like: You can have some set of known exhaustive roots and periodically delete anything not still reachable from them. Or you could have a lifecycle option, analogous to arenas (region-based memory management). Etc.