We picked the wrong company to put us on a WooCommerce platform and they almost put us out of business. The site is stable now, but the speed is inconsistent. We have a good hosting company and need someone that can look at the code and find what is causing the site to slow down. Everyone we have talked to is unable to find the cause.
Jason makes a great points there, but the speed issues could also be related to the very structure of your site. Many modern Wordpress themes rely heavily on JavaScript to load things like sliders, widgets and even page content.
You should use a well-supported, modern theme that is built for speed.
Page caching can make a huge difference, but in a lot of cases there are 2-3 page items that should be made static content rather than dynamic JavaScript content.
