Domains, delivery and craft

What is Code review?

A second person reading a change before it ships, checking correctness, security, accessibility and whether it matches how the rest of the codebase works. On a solo project the equivalent is a checklist and automated gates, because you cannot review your own assumptions.

Also called: peer review · pull request review

What review catches that testing does not

  • Assumptions that happen to hold today and will not next month
  • Security mistakes that produce no visible symptom
  • Accessibility regressions no automated scanner detects
  • Inconsistency with existing patterns, which accumulates as friction
  • Comments that describe intent inaccurately, which is worse than no comment

The solo substitute

Build-time gates that throw. This site refuses to build if a page is orphaned, if two pages target the same keyword, or if a comparison fails to name where each side wins. A gate is a review that cannot be skipped when you are in a hurry, which is exactly when review is skipped.

Review the diff, then the whole file

A diff shows what changed; it does not show what the change broke elsewhere in the same file. Reading the surrounding code catches the class of bug that only appears when two changes interact.

Where this is covered in depth

A definition can only go so far. Technical SEO, in the order the problems actually block you covers this properly — 4 minutes, free, no email required.

Who wrote this

Anas Bin Masud builds e-commerce sites and does technical SEO for businesses in the UK, Canada and Pakistan. These definitions come from client work rather than from a content brief — where an entry describes a mistake, it is usually one found on a real site. More about how I work.

Related terms

All 184 terms in the glossary →

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