Change Conventions Completely

Keep the established convention or replace it through an explicitly bounded complete migration. A locally preferable pattern is not enough reason for an isolated exception.

Consistency creates cognitive leverage: learning how one place works should help readers understand another. Differences should convey meaning rather than demand arbitrary relearning.

Activation evidence

Apply when current-task evidence identifies an established convention, a proposed alternative, and the category and boundary governed by that convention.

Compare at the convention's level:

• Naming, style, or organization: establish the shared policy from guidance and representative occurrences. Fields such as createdAt and updatedAt have different meanings but can follow one timestamp-field naming policy; matching behavior is not required.
• Behavioral contracts: before merging contracts, compare purpose, inputs and outputs, invariants, failures, lifecycle, ordering, callers, ownership, and compatibility. Similar spelling or syntax alone does not prove equivalent responsibilities.

Keep intentional role and semantic distinctions explicit. A common naming policy does not require identical types or behavior, and identical names do not justify merging distinct read and write models.

Decision rule