A well-architected caching system can help reduce the load on MySQL databases and increase application performance, but it also introduces setup complexities and potential issues such as inconsistent data and thundering herd problems. Caching systems like Redis and memcache are popular distributed caching solutions that can be used to improve application performance by reducing the number of database queries. When implementing caching with MySQL, it's essential to consider data consistency and cache expiration strategies to mitigate these issues. Additionally, a caching system like PlanetScale Boost can simplify the process of adding caching to an application by living within the existing Vitess database cluster.