This is a great example of not understanding the scaling problem of IoT. Not only is the above (quasi-)transaction rate modest by IoT system standards today, but Cassandra is not doing real-time analysis or ad hoc querying of complex relationships across those transactions at the same time, which is usually a requirement.

I know of a production IoT system in the private sector that does 1.5 trillion (quasi-)transactions every 10 minutes, so almost three orders of magnitude higher throughput. Cassandra is an okay choice for storing IoT data but it isn't real-time in the sense that you can do immediate, fast queries about the relationships across those records as they are hitting the system.