Fifty Years of the Same Basic Question

Every era of software engineering has asked the same underlying question. Before this code ships, who checks it, and how? The history of code review is really the history of that single question, answered five different ways across five decades. Each answer reflected the tools, team sizes, and risk tolerance of its moment. Understanding this full arc matters now more than ever, because AI has just introduced the sixth answer, and it looks nothing like the previous five.