For ten years I built AgriTech apps used in fields with no signal. The apps could not assume the network existed — and that single constraint reshaped every layer.
Capture locally, always
Every write hits local SQLite first and returns immediately. The UI never waits on the network. This makes the app feel instant, and it means a dropped connection is a non-event rather than a crisis.
Sync must be idempotent
When connectivity returns, a durable, ordered queue replays operations to the server. The golden rule: replaying the same operation twice must be safe. Idempotent endpoints and client-generated IDs make retries boring, which is exactly what you want.
Conflicts are a product decision
Two agents editing the same record is not just a technical problem. Last-write-wins, merge, or manual resolution — each is a product choice with real consequences. Decide it deliberately, per entity, not by accident in a catch block.
The payoff
Across 50+ apps and 15+ countries, the offline-first foundation is why field teams trusted the data. No lost registrations, no phantom procurement records — just apps that worked wherever the work happened.