Thanks for sharing this. Fascinating!
I'm a big fan of serving content APIs as static assets like you are doing here. Especially good for content which changes infrequently (a few times a day rather than many times a minute).
Static site generators typically make it simple to publish a structured data view like a JSON or XML feed of content alongside content pages as HTML (such a bonus!), but it is interesting to see that you've separated the API generation entirely as a Hugo build. (presumably for compile speed?)
I work at Netlify and am something of a JAMstack enthusiast. I'd love to learn more about the experience of designing and building this. If you'd be interested in doing more of a write up, or just sharing any of the learnings from along the way, I'd love to chat.