I host my blog on GitHub Pages, using Jekyll. One of the features I miss from WordPress is the ability to schedule posts. I found some ways to do it but they were all a bit clunky so I decided to build my own tool.
I was able to build the MVP pretty quickly because I'd already build commitcheck.com, which is a similar product. I re-used all of the logic for authentication and GitHub App setup.
For the scheduling feature I built a webhook to listen for PR comments and record the scheduled PR in a DB. I then added a cronjob to check when PRs need to be merged. This design allowed me to build something quickly. I can iterate on it in the future if I have any problems scaling.