Modern mobile application development requires a well thought-out plan for keeping user data in sync across various devices. This is a thorny problem with many gotchas and pitfalls, but users expect the feature and expect it to work well. For iOS and macOS, Apple provides a robust toolkit, called 云Kit API, which allows 开发人员 targeting Apple platforms to solve this synchronization problem. In this article, Toptal Software Engineer 保罗年轻 demonstrate how to use 云Kit to keep a user’s data in sync between multiple clients.