Capital One employs several strategies to optimize data storage costs, including the use of Amazon S3 Lifecycle policies to manage data retention and transition older versions of data to more cost-effective storage classes like S3 Glacier and S3 Glacier Deep Archive. They also utilize S3 Versioning and S3 Intelligent-Tiering to ensure efficient resource usage and minimize unnecessary expenses. By analyzing usage data and implementing tailored lifecycle policies across different S3 buckets, they can effectively manage storage costs while maintaining data durability and accessibility.

Enabling versioning on S3 buckets allows Capital One to recover from accidental deletions and application failures more easily. However, it also means that all versions of data objects are stored, which can lead to increased storage costs if not managed properly. To mitigate this, Capital One implements lifecycle policies that help manage the retention of versioned data, ensuring that older versions are transitioned to more cost-effective storage classes after a specified period, thus balancing data management needs with cost efficiency.

S3 Glacier and S3 Glacier Deep Archive provide Capital One with a low-cost solution for archiving data that is infrequently accessed. These storage classes are particularly beneficial for long-term data retention, allowing Capital One to meet compliance and audit requirements while minimizing storage costs. By transitioning older versioned data to these classes, Capital One can significantly reduce expenses associated with storing data that is rarely retrieved, while still ensuring that the data remains secure and durable.