Shopify app front end development

Hi there, We need a developer for a Shopify App we are building. We want to create an app which Shopify users can install on their store to improve the basic search function. We will provide a separate backend system to handle indexing and searching functionality which will integrate with this system via an API. We need a server hosted system for the middle and front layers which can do the following: - OAuth integration - Shop access token management and persistence - Read the inventory: products, categories etc and store into a database - A Shopify admin screen for the app, allowing re-index of products - Admin screen written using latest shopify Polaris + React - Script tag integration into the shop theme - Search popup when user enters search term containing suggestions, integrated with theme. Must show name, image thumbnail and price of product - Search page showing relevant product results, integrated with theme - Search popup and search page customizable look and feel - Integration with our search service backend for indexing products and running searches, API details will be provided - Integration with Shopify billing for a number of different pricing tiers (although the app will be free to use for all users for the initial few months) - Help with putting the app live in the Shopify app store once development is completed We would like to take advantage of Shopify's recommended stack and available libraries, so node.js / react would seem like the most preferable tech stack but we're open to ideas. We have not yet decided on the pricing structure that we will charge to users. We are just looking for the first step of the app development for this project. Note: we do not have our own Shopify store. Thanks for reading!