I gave it a complete database migration of our app, opus failed hard each time... Untyped Json b for some rows, no proper normalisation, falling back asking me questions in between.

Fable just did it, clean code, one timeout with a hanging bash script, fixed a couple very old very structural bugs in the codebase

How did you do this impressive amount of work and verify that it did it perfectly all in one day?

I told Claude to do it yesterday evening, checked in during my nightly break.

I am not sure it's perfect, and it will need further validation

This morning I looked at code samples & checked if all unit/integration and e2e pass & perfomance tests pass

I also generated a postgres schema diagram.

Aka I did probably 2 hours of work, rest was not me

The opus try was last month