This WordPress site uses a heavily-modified commercial theme built on the Genesis framework, has been around for many years, gets a lot of traffic, and serves the business well. I’ve included it as a portfolio item not because of any grand improvements or sexy features I’ve added, but to point out that success as a developer often requires more than programming skills.
When I started working on the site it was running very slow, there were many plugins that were no longer supported and some that no one remembered what they did or why they were there. I was originally tasked with cleaning things up and improving performance, which involved cloning the site, investigating every plugin and wither deleting them if they no longer did anything useful or finding a replacement if they were outdated and therefore posed a security risk. After that, we made some theme tweaks, added a couple of new sections with new sidebars and widgets, revised the template for a data service, updated the site to use https:// protocol, and so on — all without causing any significant downtime. Programming skill was necessary, of course, but the most important requirement was an ability to be very, very careful.