Offline-First

ELI5 - The Vibe Check

Offline-first means you design your mobile app assuming the network is the exception, not the rule, because on a phone it genuinely is: subway tunnels, airplane mode, spotty rural coverage, a dead zone in a parking garage. The app reads and writes to a local database first and syncs with the server whenever a connection happens to show up, instead of freezing every time the signal drops.

Real Talk

Offline-first is an architectural approach where an app's primary source of truth is a local, on-device database, with changes synchronized to a remote server opportunistically when connectivity is available, rather than treating the network as required for basic functionality. It typically involves a local persistence layer, a sync engine that reconciles local and remote state, and a conflict resolution strategy for changes made while offline.

When You'll Hear This

"We rebuilt the app offline-first after users kept losing form data every time they went through a tunnel." / "The hardest part of going offline-first wasn't the local database, it was conflict resolution when two devices edited the same record."