I learn best by taking apart something that already does something and figuring out why decisions were made in which manner.

Recently I've started working with Perl's CGI::Application framework, but found i don't really get along well with the documentation (too little information on how to best structure an application with it). There are some examples of small applications on the cgi-app website, but they're mostly structured such that they demonstrate a small feature, but contain mostly of code that one would never actually use in production. Other examples are massively huge and would require way too much time to dig through. And most of them are just stuff that runs on cgiapp, but isn't open source.

As such I am looking for something that has most base functionality like user logins, db access, some processing, etc.; is actually used for something but not so big that it would take hours to even set them up.

Does something like that exist or am i out of luck?