Linting helps us avoid common mistakes and use our team's preferred style and syntax. Deprecation warnings help us know that changes may be coming soon and offer suggestions about how to migrate.
Existing linting tools and deprecation systems aren't always customizable or extensible to organization-specific checks. Some constructs are also difficult to search for with regular expressions, which is a common configuration offering.
The time leading up to and during a migration often becomes a pain, leading to all-at-once changes that slow teams down. Can we do better?