An inspector inside a basement plant room, a surveyor in a rural block, a driver between towns — all of them are offline for meaningful stretches of the working day. An app that treats this as an error state will be abandoned within a fortnight.
Offline-first means the local database is the source of truth for the session, every write is queued with a logical clock, and the sync layer has an explicit conflict policy per entity rather than a global last-write-wins rule.
The parts teams underestimate are media and identity. Photographic evidence is large, needs compression before it queues, and must survive an app kill. Authentication tokens expire while the device is offline, so the app needs a grace mode that permits data capture without permitting data disclosure.
Retrofitting this into an online-first app is close to a rewrite of the data layer. It is one of the few architectural decisions genuinely worth making before the first sprint.
Working on something like this?
We are happy to review an architecture, sanity-check an approach or tell you honestly that you do not need an external partner for it.
Talk to an engineer