Website: 
Aviarivets.com
A company trading aircraft and helicopter parts approached me with the goal of reducing their operating costs. They decided to build their website on the WordPress platform but hadn’t accounted for the difficulties of integrating multiple plugins — and, on top of that, many plugins (such as product database search for WooCommerce) turned out to be paid.
I took on the backend work, learned PHP, and wrote a free custom plugin for searching by relevant fields — which, in essence, came down to a properly crafted SQL SELECT. Then I sorted the results alphabetically, split them into pages, and added navigation between them. At the top of the list I displayed items currently in stock, followed by those available from partner warehouses, and finally those that would have to be ordered directly from the manufacturer. In addition, I implemented predictive autocomplete for the „Search” field.
Next, I arranged the site’s modules, placed the search fields, set up the loading of results, and modified the functions that control how the site behaves with various user inputs. For example, I rewrote the cart logic so that it counts unique product types, not the total number of items: if a customer adds a thousand rivets of one kind and fifteen hundred of another, the cart icon will display “2” instead of “2500”.
Essentially, the only things I didn’t touch were the site’s visual design and the WooCommerce plugin itself.
Website: Aviarivets.com