https
HTTPS for local iOS development with mkcert: generate a local certificate authority, create SSL certificates for your dev domains, and install the root certificate on a simulator or real device so Safari and your native app trust your local Rails server.
ruby
ETags let browsers skip downloading content that has not changed. What entity tags are in HTTP, then the Rails caching toolkit: stale?, fresh_when, expires_in, expires_now, public requests, and http_cache_forever, each shown with a concrete controller example.
coding
Need a real domain, subdomains, or HTTPS while developing a Rails app? nip.io gives any local IP a wildcard DNS name without touching your hosts file. How to configure Rails for it, enable local HTTPS, and quickly find your local IP address.