In this article, the author explores how Apple built iCloud and discusses the use of FoundationDB and Cassandra in their cloud backend service, CloudKit. The author highlights that Apple stores billions of databases in their extreme multi-tenant architecture. The article also draws comparisons between Apple’s architecture and Meta’s serverless platform, noting similarities in their use of asynchronous processing, stateless architecture, and layering of abstractions. The author provides an overview of FoundationDB and its use in the Record Layer, which helps manage resource allocation and scalability. The article also discusses how FoundationDB solves scalability limitations encountered by CloudKit and provides personalized full-text search capabilities. Finally, the author highlights how FoundationDB handles transaction conflicts and the importance of higher-level tools in managing these conflicts.
https://read.engineerscodex.com/p/how-apple-built-icloud-to-store-billions