[nemothekid]

>Perhaps the frontier models of 2026H2 may be good enough to start compacting and cleaning up entire codebases

I don't think this will happen - or rather I don't think you can ask someone, human or machine, to come in and "compact and clean" your codebase. What is "clean" code depends on your assumptions, constraints, and a guess about what the future will require.

Modularity where none is required becomes boilerplate. Over-rigidity becomes spaghetti codes and "hacks". Deciding what should be modular and what should be constant requires some imagination about what the future might bring and that requires planning.

[ahartmetz]

Paying down tech debt doesn't necessarily take any knowledge of future changes. Code with tech debt didn't even handle past changes well. You can usually make future changes easier just by improving how the code does what it currently does.