subdomain vs subfolder in site address

I have a main website, from which users can navigate to several web applications. I'm trying to decide if the URL for an application should be as a sub-domain or as a sub-directory, namely which of the following to use:

• myapp.my-awesome-site.cool
• my-awesome-site.cool/myapp

Is it only a matter of taste, or are there real-life considerations here (configuration, SEO, CORS, etc.)?

Solution 1:

Management is easier when it has its own (sub)domain. Cookies, HSTS header, webserver configuration, SSL certificates, cache control (especially when using a content delivery network).

If at some point you want to pull the hosting apart and migrate it to another machine/infrastructure, it's also easier.