IoT fleet telemetry & control

What this design does

IoT's defining constraint is that the device is usually unreachable: it sleeps, roams, and drops offline mid-command. The device twin pattern solves control by splitting state into desired (what the cloud wants) and reported (what the device last said) — commands write desired state, and the device reconciles whenever it reconnects. Telemetry flows the other way through an edge gateway and an MQTT broker that applies backpressure instead of falling over when ten thousand sensors reconnect at once.

The patterns it composes

• Device twin / shadow — desired vs reported state — commands survive the device being offline
• Edge gateway / protocol translation — Modbus/BLE on the factory floor becomes MQTT at the boundary
• Telemetry ingestion funnel — one hardened, budgeted path from millions of sensors to the stream
• Backpressure — the broker slows producers on reconnect storms instead of dying
• Command with intermittent connectivity — control is state reconciliation, not fire-and-forget RPC

Import it, attach your own numbers, and verify the design against failures — or read the engineering notes.