Required software development,Website Development freelancer for WordPress website really slow, need speed expert job

We have a website built on WordPress with LearnPress plugin and theme. It loads extremely slow, all of the normal things have been completed to try to speed it up but we have found that some php functions that are pulling information from the database are causing the slowness. We think that if we can async and load the pages first then allow everything else to load in after we will be able to at the very least allow the website users to better experience the site. We would like to have each section that loads show its loading and have some type of interim loading screen/box that shows its loading i.e.'Please wait while we load your course', 'Please wait while our system calculates your results' and the like. We have a developer that was working on this but constantly keeps disappearing for days on end and not giving us updates. We also feel like this type of work isn't his strong point. We need someone who can come in and get this done fast and for a relatively decent price. I will be interviewing multiple candidates and choosing one, help us get this over the finish line. The budget is negotiable, this is just here as a placeholder, please let us know what you would normally charge for something like this.

Skills & Expertise Required

software development Website Development