That’s why I always push telemetry onto a team. Concurrency and resource bugs are extremely expensive per iteration. Anything that can hint that the problem you are certain happened somewhere in a two month period was more likely to have happened in a particular week saves you a ton of work.

The human brain struggles when it has to execute almost, but not quite, the same exercises over and over again. It becomes a blur and after a while you can’t recall if you ran all of the steps this cycle (if you can’t automate the test well) and all it takes is typing “bad” when you meant “good” to end in failure. Which doesn’t sound like a big likelihood but when you’re testing a negative it’s much easier to get your wires crossed.