Large orgs avoided 'Compile All Classes' because it took forever. Winter '27 makes it targeted.
Where
Setup, Apex Classes, alongside the existing Compile All Classes action.
How
Choose to compile only invalid classes. Salesforce recompiles just the classes flagged invalid after metadata changes, leaving valid classes untouched.
Why
Full recompiles in orgs with thousands of classes were slow enough that admins skipped them, leaving invalid classes to fail at runtime. A quick, targeted recompile turns cleanup into a routine step after deployments.