This article discusses how Edge Side Includes (ESI) can be used not only for better performance but also to optimize availability during backend migration. The author explains how his client, highsnobiety.com, implemented simple edge side includes using Cloudflare Workers. The idea was to partially replace parts of the online magazine with a new frontend implementation while maintaining the existing Wordpress setup. The article covers the use case and provides an overview of the ESI toolbox features such as Includes and Fallbacks. It also highlights how Cloudflare Workers can be used for this purpose, providing code examples and discussing its benefits.