Thanks for that summary, @titani! Netlify is like a swiss army knife - useful for many, but not all, workflows, and this is useful information for folks with such large sites.
For folks who hit this thread in the future and wonder if they can fit their site on Netlify:
You’ll have to be very careful about large deploys, specifically:
- disabling as much asset optimization as possible on our side. (no article link for this one, but it will take “some time per file” which will be quite a lot of time, in case you have hundreds of thousands!)
- using appropriate resources for the build environment (cf [Support Guide] Making sure your builds use appropriate resources for Netlify's build system). Note that there is a (much) larger build environment available, in case that is needed for your site: Netlify Pricing and Plans (look for “high performance builds”)
- …such as using appropriate plugins for gatsby (image handling ones are very unoptimized and unlikely to work here if you have very large images, for instance) (cf 5 Optimizations to Get Faster Gatsby Builds Today)
- make sure you aren’t changing every file with each build (cf [Support Guide] Making the most of Netlify's CDN cache)