Sharding a database can significantly improve backup and restore performance, making it easier to handle large databases. PlanetScale's platform uses Vitess as a proxy, sharding, and coordination layer between applications and MySQL instances. Backups are taken every 12 hours by default but can be scheduled or manually triggered. In a sharded architecture, each shard can complete backup steps in parallel, allowing for quick backups even for large databases. The power of parallelization also applies to full database restores, making them faster and more efficient.