We have an existing XML processing pipeline consisting of multiple XSLT transformations using Saxon, followed by PDF generation with Antenna House (XSL-FO). Currently, I run this pipeline via the command line (e.g., using shell scripts). I would now like to expose this pipeline as a web service, optional running in a Docker container. The goal is that a client can submit XML data and receive a generated PDF in return. Important requirement: The service should be able to handle multiple requests in parallel, either through internal parallel processing or scalable deployment (e.g., via multiple containers or threads). My questions to you as experts:

• Are there any proven architecture patterns or best practices for implementing such XSLT/XSL-FO-based web services?
• Which technologies or frameworks are recommended to make the service performant, maintainable, and robust?
• Are there any known issues or considerations when containerizing Antenna House and Saxon (e.g., licensing, execution, performance)?
• What are best practices for error handling, logging, and especially scalability and concurrent processing in such a pipeline

Any recommendations — whether technical or architectural — are highly appreciated!

Thanks in advance

Marko