This is specific to my codebase I was interviewing candidates for (heavy OO). Not all of these concepts are necessary for the candidate to understand, but a fe

This is specific to my codebase I was interviewing candidates for (heavy OO). Not all of these concepts are necessary for the candidate to understand, but a few go a long way towards a great developer experience when applied correctly: - SOLID principles - The Expression Problem - DRY - Dependency Injection - Composition vs Inheritance vs Delegation - Connascence - Law of Demeter - Invariance, Contravariance, and Covariance