What evidence do we have that code review is good for spotting bugs? Because the evidence actually says the opposite - we think that code review is good for spotting bugs but what it's actually good for is knowledge sharing.
Ask engineers why they review code, and most will say they do it to find bugs. In 2013, Alberto Bacchelli and Christian Bird studied code review at Microsoft and classified 570 review comments. 44% of developers ranked finding defects as their top reason for reviewing. Only 14% of the actual comments were about defects. Five years later, Caitlin Sadowski and her colleagues looked at nine million reviewed changes at Google and reached the same conclusion.
Quoting from this article: https://thenewstack.io/kill-code-review-theater/
Ask engineers why they review code, and most will say they do it to find bugs. In 2013, Alberto Bacchelli and Christian Bird studied code review at Microsoft and classified 570 review comments. 44% of developers ranked finding defects as their top reason for reviewing. Only 14% of the actual comments were about defects. Five years later, Caitlin Sadowski and her colleagues looked at nine million reviewed changes at Google and reached the same conclusion.