Rails applications at scale often encounter issues when deleting many records simultaneously due to associations between models. To mitigate these risks, consider using `dependent: :destroy_async` instead of foreign key constraints, which can lead to timeouts and excessive locking. Additionally, be aware of the difference between `delete` and `destroy`, as well as the importance of running validations from the parent model when using `destroy_async`. Finally, safely mass deleting old data by continuously running deletes in small batches, such as with a scheduled Sidekiq job, can help prevent unintended consequences to the rest of the application. By implementing these strategies, you can ensure cleaner data deletion and improve overall performance.