What we actually do
The interesting constraint in a connected product is almost never the radio. It is the power budget the radio has to live inside, and the fact that the device will spend most of its life disconnected and still has to be correct when it reconnects.
Power
Getting idle current below a few microamps is an auditing exercise, not a clever trick: pull-up sizing, unused peripheral clock gating, regulator quiescent draw, level-shifter selection. We measure the current profile across every device state with a source-measure unit rather than estimating it from datasheets, because the datasheet figure and the board figure are rarely the same number.
Data integrity offline
Events are logged locally with sequence numbers so records queue on-device during disconnection and reconcile idempotently when the link returns. A dose, a reading or a usage event that quietly duplicates on reconnect is worse than one that is missing, because it is harder to notice.
The whole chain
Electronics, firmware, radio profile and both mobile applications from one team, built against a shared protocol specification so the two platforms cannot drift apart.
