Hey there,
From the sounds of it, you need someone modify plugin, You need a developer who understand your project and fix the bug in cart button visibility.
As my resume represent, I had more than 3 years of progressive experience in the Shopify Designing, App Development, and Modification.
I am available to chat or email and would be happy to set up a convenient time to discuss the application you’re moving.
Thank you and I look forward to Opportunity to work with you.