Apache Kafka, Apache Cassandra, and Apache Spark Streaming are powerful technologies that can be used together in an architecture to tackle various use cases. Kafka is a massively scalable pub/sub messaging system designed for modern event streaming, while Cassandra is a distributed database management system. Spark Streaming can help enrich data, making it more meaningful and useful. The combination of these technologies allows for efficient movement of data out of legacy systems, handling microservices meshes, reducing the costliness of reads, and managing log events effectively. By using Kafka, Cassandra, and Spark Streaming together, organizations can provide better customer experiences and improve their overall data infrastructure.