IndexedDB

Implementing conflict resolution for offline-first applications where users edit the same data across multiple devices simultaneously is difficult. Developers must choose between last-write-wins, operational transforms, CRDTs, or manual resolution flows.

IndexedDB's low-level API is verbose and historically callback-heavy, requiring external libraries for usability. It lacks JOINs and advanced relational query capabilities, making complex data queries difficult.

Browser-based offline-first applications must gracefully handle storage quota-exceeded errors by pruning data, compressing payloads, or allowing users to clear cached content. Managing storage limits adds complexity to application logic.

IndexedDB exhibits subtle cross-browser differences and quirks. Schema changes require careful versioning and migration logic, adding complexity compared to simpler storage solutions.