eg a large organizations like a bit telco may have multiple applications that update customer records.
There is hardly any reason to use stored procedures anyway, when your favorite mysql library supports multiquery.
The alternative is the old StoredProc_v1, StoredProc_v2 etc in the database and have the application check what's available. This allows you to roll the parts independently.
The big advantage with stored procedures is they can benefit from the DBMS caching and applying additional optimisations (depending on the DBMS of course).
One way that works is make sure you make a simultaneous tag of your code and stored procedure that works with it. You really want development to run hand in hand with stored procedure development, not as two parallel processes.