I recommend you dont touch network_mode unless you absolutely need it

Most services shouldnt need the network_mode, just gotta port forward/translate most of the time

Minor security through obscurity thing you could implement: buy you own domain through cloudflare for ~$10/year. Use their proxy so that your public IP doesn’t resolve to your home public IP like it does now with DuckDNS. If you want to get fancy, you can also use their API with fail2ban to block connections after a predefined number of login failures.

Go to public.cyber.mil and download the appropriate stigs for your stuff, review them, and apply the settings. Always a good start to improving the security.

Audit-ssh and testssl.

Audit ssh shows all the algorithm in use and setting and shows then colored format like red bad and so on…

Same with testssl, which tls supported ? Https redirect ? What cipher suites etc … again all color coded.

Both available via homebrew for Mac.

If you use Mozilla recommended for ssh and ssl you should be fine

yes, there are professional third party cybersecurity auditors you can hire, but I doubt anyone here would ever need them.

Please people, stop being paranoid about your security. close up all unnecessary ports, and that's what you can do on your end. whatever else, if the service binding to an open port has security vulnerabilities you don't know, the project team may very well be unaware of it either, and there's nothing you could do.

also, if you have multiple users using your service, then it's their password strength that you should be worrying the most, not your infrastructure.

Check Wazuh and Greenbone, but it requires a high learning curve so have fun learning the basics