NodeJS, MongoDB - Mobile back-end improvement

CONTEXT We are launching a startup about a marketplace that will link influencers and businesses willing to promote themselves on social media. We already have a tailor-made website that you can visit on [login to view URL] We already have a first version (see mock-up [login to view URL]) of the app (coded in Swift, NodeJS and MondoDB) that was tested live with users and received plenty of feedback that will require the design of our app to be reviewed and new features to be added in the back-end. High-level, the features that were developed so far are: 1. Businesses will be able to post offers on the marketplace (e.g., business is willing to offer a free meal for 2 people and give 50 euros cash in exchange of 2 posts and 2 stories on Instagram) 2. Influencers can apply to these offers or they can be invited by the businesses to collaborate (as on upwork where freelancers can either apply or get invited to a job) 3. Once there is a common interest / match between an influencer and a business, they can engage into a discussion and start negotiating for a deal through a chat. 4. Once they have agreed, the influencers can share the posts and stories on the app which will track their performance. TASK Building upon our current code, you will have to add new features that are specified in the attached excel. DEADLINE We want to have the new release of our app by the beginning of June. SETUP You will be together with me (product manager) and a front-end dev INTERVIEW QUESTIONS 1) What is your experience in implementing back-end in NodeJS and MongoDB? What about marketplaces? 2) What will be your approach? 3) Please provide a high-level estimate it would take you to implement each feature