Ajax speed and other JS issues assessment and fix

We have a woocommerce install, where the speed on many ajax functions, and other these functions are very slow, we need an expert who can assess and fix where needed any code changes that would improve the speed

Please note, the works will be assessed on actual real world testing, not gtmetrix type checks, as we already have great results from this, we need someone who know how and where adjustments need to be made to deliver a quick search and add to basket function