I was approached by another developer who needed some help to finish a calendar application promised to a client.
This application was built using procedural php and jQuery using jQuery's full calendar plugin.
The code was a very messy codebase with procedural php function files all over the place and the code was not DRY at all.
I ended up helping to finish the calendar and launch it to the client. After a few feature enhancement requests I decided to refactor this codebase into a custom MVC framework I developed during my degree.
Using this framework I was able to reduce code complexity and help achieve DRY (don't repeat yourself) code. This helped with improving performance and allowed to me to introduce defensive programming into the codebase.
Check out the PHP framework I built in 2015. I adopted this framework into a solution for the client.