IaaS & Paas
https://fly.io
https://render.com/
https://platform.sh/
https://vercel.com/
https://upsun.com
https://railway.app
https://scalingo.com/
https://www.koyeb.com
https://www.alwaysdata.com/
https://www.clever-cloud.com/
https://www.heroku.com/
https://workers.cloudflare.com/

BaaS
https://strapi.io
https://appwrite.io
https://parse.com/
https://directus.io/
https://supabase.com
https://www.convex.dev
https://payloadcms.com/

DBaaS
https://xata.io
https://neon.tech
https://fauna.com
https://www.datastax.com/
https://www.mongodb.com/
https://www.couchbase.com

VPS
https://www.scaleway.com/fr/
https://www.digitalocean.com/
https://www.linode.com/
https://www.vultr.com/

Bare metal
https://rackservice.org/
https://www.dedimax.com/
https://www.leaseweb.com/

Automation
https://zapier.com/
https://buddy.works/

IP test
ipinfo.io/92.222.68.44

Availability/reachability probing
https://atlas.ripe.net/
http://shotsherpa.com/
https://geopeeker.com/
https://www.geoscreenshot.com/
http://ipv6-test.com/validate.php

DNS
https://www.whatsmydns.net
https://dyn.com/free-dns-test/
https://www.dotcom-tools.com/DNS-lookup-tools.aspx
http://www.dnsstuff.com/tools
https://dnschecker.org/all-tools.php

Site perf test
https://developers.google.com/speed/pagespeed
https://tools.pingdom.com/
https://latency.apex.sh/
https://gtmetrix.com/
https://www.webpagetest.org/

TLS
https://wiki.mozilla.org/Security/Server_Side_TLS
https://mozilla.github.io/server-side-tls/ssl-config-generator/
https://www.ssllabs.com/ssltest/
https://tls.imirhil.fr/https

Client tests
https://www.ssllabs.com/ssltest/viewMyClient.html # browser tls
https://speedtest.net <a href="?addtag=speedtest" title="Hashtag speedtest">#speedtest</a>

PUT vs PATCH (and other considerations)
http://stackoverflow.com/questions/24241893/

200 vs 201
http://stackoverflow.com/questions/1860645/