Headless Shopify Development with React

We've recently build site on headless. We have a few teething problems that need sorting. To then lead on to bigger project of site re-build. I have the design done already an need an experienced developer to a) fix issues and b) work with us on long term build of site... (Budget: £5000 - £10000 GBP, Jobs: API, CRM, Frontend Development, HTML, JavaScript, PHP, Python, Shopify Development)