a) Set up a "Site" and add caching and HTTPS with ease. Inject analytics with one button press on their web GUI. Free (credit) tier and services as low as $1/month after that.
b) Create an "Edge App", basically program your own CDN/DNS, deployed to Fly's 18 servers, in the same language you use on the front-end, the latest Javascript. Use their API to cache however you like, re-route `/pathnames`, and so on. Even resize or watermark images based on the request. Or just import something from NPM.
c) Their "Wormhole" product lets you load-blanace without nginx, just by adding some text to your Dockerfile. I've deployed a swarm to Docker across several VPS using this, no nginx config required.
You can start with no credit card, only caveat is you need a DNS with flattened CNAMEs (for root) or ANAMEs or ALIASs (unless you only wanna use subdomains).