Hosting updown.io started with a single OVH server and quickly grew to more server, first it was DigitalOcean VMs and we were very satisfied about them. But we then noticed some shortcomings about #IPv6 networking, although DigitalOcean supports it they don't provide the standard IP range to each VM (by choice) and thus have to block port 25 to avoid other machines being blocked in case of spammer. This is not good for us it means we can't monitor IPv6 SMTP servers properly, that's why we switched to @Vultr (one of their main competitors) which provides similar prices, more locations, and true IPv6 support with no blocked ports. Of course they offer less tools and the support is probably better at DigitalOcean but so far we're happy with @Vultr.

We still use some @OVH servers (which offers tremendous price/performance ratio) for the main web and database server + 2 of the daemons. In addition to this, we also have 2 DigitalOcean VMs for the secondary web and database server and for the automatic TLS termination proxy used to automatically issue Let's Encrypt certs for status page custom domains (for these servers the IPv6 port block is not an issue)