My sense was that Comcast is far bigger than cloudflare, and from my googling that appears to be the case.

Xfinity: $52 B revenue 2017

Comcast holdings (the parent of xfinity, couldn't find numbers for xfinity): 184,000 employees

Cloudflare: < $ 0.2 B revenue 2018, several thousand employees (looks like less than 2000)