Hurricane Electric?
 

Which major SaaS use H/E?

I'm seeing this service provide A LOT in my logs

Hi $5,

Hurricane Electric is a large global network that is one of the most "peered" in the world so virtually every network connects to them. As far as ipv6 goes, they're the most peered. Some companies buy "full route transit" from them, but most, like us, simply meet them over various peering exchanges to exchange with each other "direct" traffic. So what does this mean.. they are a relevant global network operator. Most hosting companies and networks have established peering connections with them. If you are wanting to know how do they rank qualitatively as a bandwidth provider, because they do sell bandwidth and colocation, my advice would be that best results can only be achieved by connecting to them and other global carriers, simultaneously.

https://bgp.he.net/report/peers

Hope this helps

Brad