At my job (junior web developer), I started out working on some object based software that was designed to pull data from a DB and turn it into websites for the frontend. After some time with this, my supervisor had me move on to to their data entry portal which is based on PHP framework, Yii. It uses the framework to create an administration portal using a theme called Katniss (themeforest) and custom database design. Be sure to check out Id Tools.
Yii is not intuitive at first; it takes some time investment up front, learning the framework using tutorials. There are tons of free online documents as well as books available. I just looked up some tutorials on YouTube and followed along by creating a simple instance of Yii on the server at work. After learning the system and the syntax, Yii became a matter of learning the available plugins and features; And not plugins like WordPress.
A prerequisite to learning Yii is to know basic software development concepts one of them being model-view-controller. That's all that Yii is based on. If you know what an mvc is pretty well, you can latch on to the Yii structure, after that the Yii syntax. I would recommend it to some one else but the downside to this recommendation is that I haven't work with any other frameworks before. I don;t c and java libraries count, although some (people on the internet) argue this they count.
I'd like to check out some other PHP frameworks to see what they have to offer. Let me know if you have any experience with another PHP frameworks or what you think about Yii if you've used it, in the comments below