Your Code Review Checklist: 14 Things to Include
Codementor Blog, Jul 6, 2020
https://www.codementor.io/blog/code-review-checklist-76q7ovkaqj
A Quick Guide for Code Reviews
Andrew Berry, Lullabot, Jan 4, 2012
Some items such as using SimpleTest are out of date, but still holds up.
https://www.lullabot.com/articles/a-quick-guide-for-code-reviews
A guide to auditing, reviewing, and improving a Drupal module
Jacob Rockowitz, Feb 24, 2022
https://www.jrockowitz.com/blog/audit-drupal-module
Your Team’s Technical Guide to Drupal Code Reviews
Andy Carlberg, Bounteous, March 23, 2022
https://www.bounteous.com/insights/2022/03/23/your-teams-technical-guide-drupal-code-reviews
PHP Static Analyzer, PHPStan
See Development Tools for more info.
PHP Code Sniffer, PHPCS
See Development Tools for more info.