The relationship between Apache Kafka and machine learning (ML) is an interesting one that I've written about quite a bit in How to Build and Deploy Scalable Machine Learning in Production with Apache Kafka and Using Apache Kafka to Drive Cutting-Edge Machine Learning. This blog post addresses a specific part of building a machine learning infrastructure: the deployment of an analytic model in a Kafka application for real-time predictions. Model training and model deployment can be two separate processes. However, you can also use many of the same steps for integration and data preprocessing because you often need to perform the same integration, filter, enrichment, and aggregation of data for model training and model inference. We will discuss and compare two different options for model deployment: model servers with remote procedure calls (RPCs), and natively embedding models into Kafka client applications.