Scale & Polish E-Commerce Dashboard

Project Overview:
I have a working prototype of a multi-channel seller management app called RIVA. It allows sellers to manage product listings, pricing, and inventory across multiple platforms (Meesho, Flipkart, Amazon, Myntra) from a single dashboard. The current MVP has a Node.js/Express backend, SQLite database, OTP-based authentication, a basic AI assistant chat widget, and an Android APK wrapper built with Capacitor. It’s currently deployed on Render.com.

I’m looking for an experienced developer to take this from prototype to a stable, production-ready product.

What I need help with:

Review and refactor the existing backend (Node.js/Express) for scalability and security
Fix known issues with the Android APK (connectivity/WebView configuration problems)
Improve the database layer (currently SQLite — advise on migration to PostgreSQL/MySQL if needed for scale)
Polish and modernize the frontend UI/UX (currently plain HTML/Tailwind)
Add real integrations with marketplace APIs (Meesho, Flipkart, Amazon Seller APIs) for live sync — this is the core feature
Set up proper CI/CD and production hosting (moving off free-tier Render)
Build a stable iOS version (currently web/Android only)
Ongoing support and feature additions post-launch

Ideal skills:

Strong experience with Node.js, Express, REST APIs
Experience with e-commerce marketplace integrations (Meesho/Flipkart/Amazon Seller APIs a big plus)
Mobile app experience (Capacitor, React Native, or native Android/iOS)
Database design (SQL/NoSQL)
Clean, well-documented code and clear communication

Deliverables:

Production-ready backend with proper error handling and security
Working Android and iOS apps
Documentation for future maintenance
Source code handover with clean Git history

Budget: 20000-30000
Timeline: 1 month

Please share relevant past work (especially any marketplace/API integration projects) when applying.