[londons_explore]

The full test suite is probably tens of thousands of tests.

But AI will do a pretty decent job of telling you which tests are most likely to fail on a given PR. Just run those ones, then commit. Cuts your test time from hours down to seconds.

Then run the full test suite only periodically and automatically bisect to find out the cause of any regressions.

Dramatically cuts the compute costs of tests too, which in big codebase can easily become whole-engineers worth of costs.

[tele_ski]

It's an interesting idea, but reactive, and could cause big delays due to bisecting and testing on those regressions. There's the 'old' saying that the sooner the bug is found the cheaper it is to fix, seems weird to intentionally push finding side effect bugs later in the process because faster CI runs. Maybe AI will get there but it seems too aggressive right now to me. But yeah, put the automation slider where you're comfortable.