Shopify web development

We are looking for a potentially long-term shopify developer to work with our design and marketing team to launch lading pages, banners, fix bugs, etc on our ecom. Based on current schedule and projects, the work load is expected to be 20 hours a week, depending on the skill level.
Will need somebody has experience with shopify platform (must have), coding knowledge, someone that's responsible and responsive to our project requests.