Coding Conventions
G24: Teams that follow coding standards consistently produce codebases where any developer can read any file with minimal friction. Standards cover naming (camelCase, SCREAMING_SNAKE), spacing, brace placement, and file organization. The specific rules matter less than applying them without exception. Inconsistency forces every reader to context-switch as they navigate the file.
Eliminating Magic Numbers
G25: A magic number is a literal value in code whose meaning is not self-evident. 86400 is a magic number. SECONDS_PER_DAY = 86_400 is not. Named constants serve three purposes: they document intent, they make global search-and-replace safe, and they centralize the value so it's changed in one place. This applies to strings too — "application/json" should be CONTENT_TYPE_JSON.
Code Challenge
Replace all magic numbers with named constants.
Key takeaway
Magic numbers are as bad as magic spells — nobody knows what they do or where they came from. Name them.