The de-facto workflow orchestrator for data pipelines. Astronomer's commercial offering keeps OSS Airflow vibrant.
From Wikipedia
Apache Airflow is an open-source workflow management platform for data engineering pipelines. It started at Airbnb in October 2014 as a solution to manage the company's increasingly complex workflows. Creating Airflow allowed Airbnb to programmatically author and schedule their workflows and monitor them via the built-in Airflow user interface. From the beginning, the project was made open source, becoming an Apache Incubator project in March 2016 and a top-level Apache Software Foundation project in January 2019.