* How to configure caching and caching rules - please note there are few ways (query strings, headers, parameters, cache enabled only on single method etc.) to specify how to cache responses.
* Attach your REST API on custom domain as a regional endpoint (instead of edge-optimized, since regional endpoints are more configurable)- create ACM certificate (per each region, and one for CloudFront), create own CloudFront distribution (think: multi region deployment), add DNS record in Route53 and configure WAF (some magic DDoS protection).
I took me a lot of time with CloudFormation to get through where I am today and yet I think I would be grateful if someone will share his knowledge gained on more sophisticated use-cases than just 'Hello World'.