Wrote a Tutorial on How to use Custom Function on HarperDB by building a curation site.
https://blog.hrithwik.me/how-i-used-harperdb-custom-functions-to-build-a-web-app-for-my-newsletter
https://blog.hrithwik.me/how-i-used-harperdb-custom-functions-to-build-a-web-app-for-my-newsletter