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EngineeringProcess5 min read
Why code review fixes the wrong things
Most review comments are about style and bikeshed details. The expensive bugs slip through because nobody's looking at the right altitude.
Code review as practiced in most teams catches typos and naming preferences but misses the architectural mistakes that will cost months later. The format is partly to blame: line-by-line diff view rewards local attention.
Where the expensive bugs hide
- Decisions made before the diff ("this should be a queue, not a sync call").
- Coupling that's only visible at the module level.
- Performance traps that only matter at production scale.
- Security issues that require understanding the threat model.
Review the design, not just the diff
Push design decisions earlier — a short doc before the PR, a Loom video walking through the approach. The PR then becomes implementation review, where line-by-line scrutiny actually fits the problem.
Review the decision. The diff is just paperwork.