The Apache Sling project just released the latest version of the Apache Sling Starter, version 11. This artifact is an aggregator of the modules making up Apache Sling and is used by many downstream applications as a basis for the "stable" version of the Apache Sling codebase.
This new Resource Filter API allows AEM / Sling developers to be significantly more succinct and readable and how they perform common repository traversals. It's not a pure replacement of JCR queries, but for simple content structures you can do a lot more with a lot less code.
Unfortunately, AEM did not provide a mechanism to interact with Markdown content, nor were any of the Java markdown libraries compatible with OSGi. Recently, I worked with the Flexmark team to produce an OSGi bundle version of the Flexmark markdown library.
I've seen and written a lot of background jobs in my career and in my experience, they are most common culprits to hard-to-diagnose issues in website operations. This is why, with background jobs, it's even more important than your standard component code to ensure the job executes successfully.