[sneak]

In my view, it‘a a rather lot of work. The hard parts are probably less visible: combatting abuse of the free build system, sysadmin/scaling stuff, et c. Getting build scripts running and static pages on a webserver, their main function, is relatively straightforward.

If you want to build one just for yourself, that is probably a weekend project. Doing multitenant safely is likely where it gets a lot more complex.