With mass virtual hosting (not virtualisation, think in terms of vhosts in Apache) resource sharing and security issues that aren't easily fixed with some UID/GID quota tricks and as such we got chrooted FTP, SSH and SCP, then OpenVZ at some point, and LXC. Later down the line we got container sand cgroups and even later, cgroupv2. All of them with similar goals in mind: shared resources, but strong enough isolation to not have unwanted side-effects.
This is still something that exists, but isn't really used this way (as far as I can tell - only ISPConfig seems to do this?), because containers were then also used as stateless packaging methods where you don't edit anything in a running container, but rather just re-deploy the whole thing. That is of course not a good match for the article, but there is nothing preventing this from being done in a container. Heck, if you have classic shared storage (i.e. NFS) you could get any container hosting company to do this without them knowing it.
But you'd still be on the hook for managing the container lifecycle...