if you happen to self-hosted your own website(like this one) on a VPS
and you also happen to use Cloudflare let all your traffic flow through it
one day, you made some UI changes to your site, beautifully tested on local, you pushed and redeployed, and then you sit and wait for your brand new UI to appear
but it doesn't
turns out, beside preventing bot and ssl termination, Cloudflare also cache your static files(HTML, CSS, JS,...) on its edge server, effectively made them faster to retrieve, but also keep them stale, not up-to-date with the latest change until the cache expired
seem simple enough, but with a noob like me, it was 2 hours spending debugging and with countless browser refresh and asking "why??? it worked on my local..."
but after all that, you just need to go to Cloudflare Cache Configuration and click Purge Everything (also remember to clear your browser cache)
and also you can set up for Cloudflare to auto renew the cache when new changes is added, but I'm too lazy to figure that out now
welp, that's 2 hours of my life wasted...