Joel Andrews, a developer at Kashoo, shares insights into the challenges and solutions of managing data synchronization using Couchbase Mobile and Sync Gateway. Initially, as the complexity of document types increased, maintaining sync functions became cumbersome, leading to code duplication issues. To address this, Kashoo developed a standalone utility called synctos, which facilitates the creation of sync functions without duplicating code. Synctos uses a code generation approach that allows developers to define document types declaratively, thus streamlining validation, authorization, and channel assignment processes. The utility, released as open-source software under the MIT license, has evolved to include five robust phases that enhance data management and reduce manual effort. It includes features for assigning access, validating document properties, and ensuring channel authorization, significantly simplifying the creation and maintenance of sync functions. By using synctos, developers can produce detailed error messages and enforce document immutability, roles, and channel access, ensuring secure and organized data synchronization across multiple databases.