> What I mean is that a big refactor might take 9 months to do atomically whereas it could have been done in 3 months as a massive single PR. However I guarante

> What I mean is that a big refactor might take 9 months to do atomically whereas it could have been done in 3 months as a massive single PR. However I guarantee you we'd have spent 6+ months cleaning up unexpected issues that show up after merging the giant PR. Yes, one of the lessons of process engineering a la Deming is that the important thing is to get the process under statistical control, which typically means minimizing the variance inherent in a process, rather than the mean. Doing a big refactor might minimize the mean time to completion, but it will typically have a long tail which occasionally bites you and costs you dearly. The approach that minimises the variance might take longer in mean but generally when it's done it's done. Fewer unexpected surprises.