Flexmark for Markdown processing

I have been planning on using the flexmark-java library for my markdown-to-HTML conversion, but I am concerned for the future of the project. The lead developer has not been active on github for a year now, which means pull requests are not being merged and the project has not moved at all. Alternatives include commonmark-java (last updated November '22) and Jetbrains's markdown (a kotlin project, last updated December '22 but not nearly as feature complete).

I'll stick to flexmark-java for now.

I've been wondering about the structure/architecture of my AWS lambdas. I'd like to avoid the monolith that bascule became, so I am wondering about splitting the code into lots of smaller lambda functions. I don't know if that's testable, or sensible - more lambdas means more cold-start waiting time, and it might me more complicated testing. But it could make the project more modular, and more microservice based.

So my first question is - should the lambda which responds to file uploads be responsible for markdown conversion? I am going to say 'no' and trial some ideas. File uploads could be other files besides markdown (images, etc), so perhaps the upload handler just handles the uploads, and passes it to another lambda for processing.

But how to pass execution to another lambda? Perhaps a message queue like AWS SQS or SNS?