Deploying the front end
The front end is a client-side rendered SPA, so there are many options for deploying it. We went with Netlify.
First create a site on Netlify via the web app, then take note of the API ID (under Settings). Also generate a personal access token (under User Settings). These go in the GitHub secrets NETLIFY_AUTH_TOKEN and NETLIFY_SITE_ID.
Redirect rules are also required for the app to work correctly.
That's about it. Check out the workflow configuration for the details.
The final step is to add the domain to the CORS whitelist:
heroku config:set PROPS_ADDITIONAL_ALLOWED_ORIGINS="https://your-site.netlify.com" -a sapling-planning