There are several Java-based open-source workflow engines that are widely used for production purposes. Here are a few options to consider:
Apache Airflow - Airflow is a popular workflow engine that provides a flexible platform to programmatically author, schedule, and monitor workflows. It supports a wide range of data processing tasks and offers a rich set of features, including an intuitive user interface, DAG visualization, and extensibility.
Activiti - Activiti is a lightweight and scalable workflow and BPMN platform that enables users to automate business processes and workflows. It offers a powerful and flexible workflow engine that can be easily integrated with other systems, including Java applications.
Camunda - Camunda is a lightweight, open-source workflow engine that provides a powerful platform for business process automation. It offers a user-friendly interface and a robust set of features, including process modeling, task management, and workflow automation.
Netflix Conductor - Netflix Conductor is an open-source workflow orchestration engine that supports distributed, microservice-based architectures. It offers a set of powerful features, including task scheduling, event-driven workflows, and parallel processing.
Each of these options has its strengths and weaknesses, so it's essential to evaluate each one based on your specific needs and requirements
