I did the thing that everyone says you shouldn't do -- I spent 6 months writing a book without getting market validation. I'd been building Python apps on top of AWS Lambda using Flask, and I thought it would be really cool to release a step-by-step guide to building your own serverless Flask web apps, so I did. It took a lot longer than I anticipated, and I think there's some sales flow refinements that I can do, but it's live: https://compellingpython.com/
I got three good technical reviewers to look through it, so I believe the content is solid, but if you check it out please let me know where improvements can be made! Thanks, this is my first product of this type.