Unit tests cover parsing, validation, units, and deterministic geometry. Add property and numerical tests before implementing solvers. Integration tests should replay anonymized MQTT events into disposable PostGIS. Laboratory timing tests need at least three gateways, a common static transmitter, offset/jitter measurements, reboot tests, SF/RSSI sweeps, and long-term stability. Field evaluation compares estimates with synchronized reference GNSS and reports distributions and failure rates, never only a best-case accuracy.