On the contrary, when using SaaS based programming environments, aka iPaaS, it really feels like using Smalltalk and Lisp images.

With a very big difference, at least I could backup Smalltalk and Lisp images.

Unless you give them a tool which lets them execute arbitrary code in the running image.

Or at least this works wonderfully in Clojure via the nREPL.

On the other hand, ai agent harnesses work a bit like image based system - think: claude --resume