This document discusses sustainable approaches to content management for mobile experiences at museums. It recommends: 1) Developing modular, tiered architectures like model-view-controller to allow flexible integration of content and prevent monolithic designs. 2) Using a content management system (CMS) to store digital assets and metadata that can be exported and used across different platforms and technologies over time. 3) Conceptualizing content, navigation, and digital experiences as separate "layers" that can be updated independently, similar to the layers in a sandwich, to ensure sustainability and flexibility amid technological changes.