This document discusses using Spark Streaming for IoT applications and the challenges involved. It notes that while Spark simplifies programming across different processing intervals from batch to stream, programming models alone are not sufficient as IoT data streams can have varying rates and delays. It proposes a unified data infrastructure with abstractions like data series that support joining real-time and historical data while handling delays transparently. It also suggests approaches for Spark Streaming to better support processing many independent low-volume IoT streams concurrently and improving resource utilization for such applications. Finally, it introduces the Device-Model-Infra framework for addressing these IoT analytics challenges through combined programming models and data abstractions.