Any best practice guide for developers to avoid causing memory leaks to database?

My production database recently was hit by a shared memory issue after running fine for more than 5 years. As usual support ask us to increased the DB's memory. However seeing that this will required downtime and it's hard to get downtime for a production instance we drill further and manage to find the root cause of the issue. Apparently our developer scheduled a new package to run at night just recently and the package has run and hung causing ora-04031 errors. Once the job was disabled DB was running back as normal. Now the developers is asking if there's