Pulsebloom
Most small IoT projects rebuild the same plumbing: transport, storage, alerts, a dashboard. Pulsebloom is a Python framework that provides that plumbing with swappable backends, so an MQTT + SQLite prototype can become a Kafka + Postgres deployment without rewriting device code.
It has bidirectional RPC, a rules engine, and a digital-twin state layer you can query back in time. 201 tests, published on PyPI.