Can you speak more to the code server and domain set up? How do you get it to auto provision subdomains?

Sure, code-server is a web version of vscode, like the github spaces thing only selfhosted.

I have acme.sh creating the certs using let’s encrypt. I have a reverse proxy (haproxy) in front of code server. This handles ssl.

The port forwarding and mapping to a subdomain is automatic - it’s a feature of code server: https://coder.com/docs/code-server/guide

From the docs: code-server --proxy-domain <domain>