For inboxkitten.com, an opensource disposable email service;

We migrated our serverless workload from Cloud Functions for Firebase to CloudFlare workers, taking advantage of the lower cost and faster-performing edge computing of Cloudflare network. Made possible due to our extremely low CPU and RAM overhead of our serverless functions.

If I were to summarize the limitation of Cloudflare (as oppose to firebase/gcp functions), it would be ...

1. <5ms CPU time limit
2. Incompatible with express.js
3. one script limitation per domain

Limitations our workload is able to conform with (YMMV)

For hosting of static files, we migrated from Firebase to CommonsHost

More details on the trade-off in between both serverless providers is in the article