Spark is a unified analytics engine for large-scale data processing. It provides high-level APIs in Scala, Java, Python, and R, and an optimized engine that supports general computation graphs for data analysis. It also supports a rich set of higher-level tools including Spark SQL for SQL and DataFrames, MLlib for machine learning, GraphX for graph processing, and Structured Streaming for stream processing. https://spark.apache.org/

Apache Flink is an open source stream processing framework with powerful stream- and batch-processing capabilities. Learn more about Flink at https://flink.apache.org/

This project is a collection of small and focused tutorials - each covering a single and well defined area of development in the Java ecosystem. A strong focus of these is, of course, the Spring Frame