(I have no affiliation with Netlify I just think their service is neat.)
[2] https://gilly.tk
edit: formatting
Does netlify provide the actual hosting or they allow you to setup deployment to a VPS? Also if netlify does the hosting, how good is their uptime/availability?
We host the sites on our CDN, which has more than a dozen points of presence around the world. You can either let us build your site using anything you can get working on linux (see https://www.netlify.com/blog/2016/10/18/how-our-build-bots-b... for details) or build it yourself and ship the finished product to us. Nothing "runs" on our side after build, so there are no servers/VPS's which you can configure in the equation as far as hosting is concerned. We let you do a few things that you used to do with htaccess files (redirects are free; custom headers including basic auth are a paid feature)
You can check out our list of past incidents on our status page to gauge uptime for yourself: http://netlifystatus.com/
Since we use redundant DNS (NS1 + self-hosted), and use dynamic DNS response based on both location the query comes from cross product which CDN nodes are responding, we can (and occasionally do) remove, rebuild, or add CDN nodes without affecting our overall service. Since we use multiple network providers (for instance we use AWS, but we also use 3 other services), downtime at any one of our providers won't introduce any substantial problems in our network.
You don't have to use any of our clients to deploy a site; they're just options in case you'd rather build the site yourself than have us build it. I rarely use the clients (we have one in go in addition to the Node.js version: https://github.com/netlify/netlify-go and further our API is scriptable in any language and fully documented here: https://open-api.netlify.com/)
You can (and we do this for you by default) configure GitHub, GitLab, or Bitbucket to trigger a build whenever you do something at the repo. The default, free behavior builds on pushes or PR's against your selected branch and if it's a PR, shows you a deploy preview rather than publishing at your main URL: https://www.netlify.com/blog/2016/07/20/introducing-deploy-p...).
Finally you can drag and drop a zipfile with your site's built contents, if you are in a hurry or less technically inclined.
So, you don't need Node to use us and I don't think most of our customers do use that client; most build direct from their repositories.
I'm amazed at how fast the site is now: https://portfolio.stavros.io/