I need a shopify developer

We are looking for a Shopify developer to assist with growing and driving our Shopify sites [login to view URL] The main areas we need assistance with are Site optimisation User journey/flow analysis Conversion rate optimisation A/B testing Integration & Backend Services ERP, WMS, IMS & other back office integration API development App development Middleware development and management 3rd party app configuration and customisation (Recharge etc) Site Optimisation UX design UX development Site Maintenance Bug fixing and enhancements Ruby script knowledge essential Performance optimisation Development - enhance and introduce new functionalities and pages