Quicksilver is a key-value database used by Cloudflare's vast network of servers to manage configuration information, ensuring rapid responses to network requests. Initially, all servers stored the entire dataset, leading to disk space challenges as the dataset expanded to over five billion key-value pairs and 1.6 TB in size. To address scalability issues, Quicksilver introduced a caching system with a proxy mode that reduced the storage burden on individual servers by keeping only a cache, while a few special servers retained the full dataset. This evolved into a tiered architecture, with local caches on each server, a data center-wide sharded cache, and replicas on storage nodes for rarely accessed data. This new structure improved cache hit rates to above 99.99% for most instances, efficiently handling the growing number of keys and requests without compromising performance. The transition to this tiered system involved complex migrations and was executed transparently to customers, reflecting strategic improvements in system architecture and scalability.