My experience in Perl can be measured in decades, since a University friend gave me a quick introduction into how useful it can be.

Salter MiBody - BODYDATA.TXT parsing
Their desktop app is poor, and obviously windows only. 1 I wanted a more flexible solution for just reading the data into a database, maybe even into google fit. On the plus side the scales write a file onto a USB stick with a standard FAT filesystem so grabbing the BODYDATA.TXT was nice and simple. However their "TXT" file is actually binary data. I did try contact them asking for a spec but was declined. So I did some research and reverse-engineered the format. I have a working prototype on GitHub that reads and displays the content allong with some of the calculated values such as BMI. I might make a proper CPAN module at some point. 1
A simple perlmodule that can read back the value of a standard graphical webcounter. More detail can be found here.
I used to have a number of machines in my home network and the spare CPU cycles were dedicated to the SETI Project . Obviously being involved in that is all about the stats so I had written a number of simple Perl scripts to extract current user and group stats from the XML feeds that the seti server supplies. There are pages on the seti server to display the data already, but I wanted to play and not have to browse the site to get the stats all the time. I have three scripts at the moment. Sadly the API is no longer available so they no longer do anything :-{
Grabs the data for a particular user (by email address) and prints it to the screen.
Grabs the stats for a particular group (by name) and lists all the users in order of most reported blocks.
Similar to, however instead of printing out the results it stores the data in a database. You can then run it daily as a cron job and collect a nice amount of data for generating graphs of your progress against the progress of fellow team mates (will be working on these analysis scripts next).