Comment by saghm

Who said they deployed it themselves? I would expect that they made a PR (probably with some benchmarks), and that there are tests ensuring that the results are the same independent of timing, so then the author of the comment could verify whether it still worked and reproduce the benchmark results and then chose where to approve and merge based on that.

The same techniques that were used to try to prevent regressions before we had LLMs still work for LLM-generated code, provided that you actually use them. If you have an insufficient test suite and a lax policy around who reviews code before merging, you're going to have a bad time even if you only have your seniors writing the code by hand.