You can try it out below and at the bottom of most other posts.
I’m trying out doing this server-side rendered. The comments form POSTs to a Cloud Function hosted on Firebase that does the spam check, writes to the database, and triggers Netlify to re-publish the site.
My Gatsby blog theme then sources the nodes from the Firestore database so they can get added to each page.
I learned a good deal about Cloud Firestore — which I hadn’t used before — and combining Gatsby nodes from different sources together.
Does it work? Give it a go!