Resilient systems work autonomously and can synchronize - but don't need to synchronize.
* Git is resilient.
* Native E-Mail clients - with local storage enabled - are somewhat resilient.
* A local package repository is - somewhat resilient.
* A local file-sharing app (not Warp/ Magic-Wormhole -> needs relay) is resilient if it uses only local WiFi or Bluetooth.
We're building weak infrastructure. A lot of stuff shall work locally and only optionally use the internet.