Full-Stack/Backend Developer - API Optimization, React Native Subscriptions & Automation

We are looking for an experienced developer to upgrade our existing Python/FastAPI backend and implement a new subscription model in our React Native mobile application. Additionally, you will be responsible for setting up automated video rendering and social media posting workflows.

Milestone 1: Backend Refactoring (Python/FastAPI)

Completely remove the Playwright dependency to reduce RAM and CPU overhead.
Integrate a premium JSON Search API (details provided upon hire) to fetch image data quickly.
Ensure our custom extraction logic (OpenCV) and integration with our internal APIs remains intact and performs efficiently on the new data stream.
New Feature: Implement functionality to extract data directly from specific "creator profiles" as an additional data source.
Ensure robust error handling, caching, and fallback mechanisms for 99.9% uptime.
Milestone 2: React Native App Updates

Integrate a new In-App Subscription / Paywall system (e.g., using RevenueCat).
The subscription should unlock:
Access to the premium, lightning-fast search (powered by the new backend).
A completely Ad-Free experience across the app.
Handle the frontend UI/UX for the paywall and subscription management.
Milestone 3: Social Media Automation Pipeline

Set up a video rendering workflow (e.g., using Python/FFmpeg on GitHub Actions) that automatically downloads a preview video from our database, resizes it for Reels/Shorts (9:16), adds a blurred background, and overlays our app logo/name.
Orchestrate cross-platform social media distribution (Instagram Reels, YouTube Shorts, Pinterest) using an automation tool like Make.com.
Automate Firebase Push Notifications to alert users when new data is added to the database.
Requirements:

Strong experience with Python and FastAPI.
Proven experience integrating 3rd party REST APIs.
Solid experience with React Native and implementing In-App Purchases/Subscriptions (App Store & Google Play).
Familiarity with OpenCV or basic computer vision extraction is a plus.
Experience with FFmpeg, GitHub Actions, and automation tools (Make.com/Zapier).
"Vibe Coders" Welcome: We highly encourage the use of advanced AI coding tools (Cursor, GitHub Copilot, Claude) to build fast and efficiently.
Ability to write clean, performant, and well-documented code rapidly.
To Apply: Please share examples of previous React Native apps where you've implemented subscriptions, as well as any backend API projects you've optimized for performance. Since this project is perfectly suited for AI-assisted rapid development ("vibe coding"), please provide a competitive, reasonable price quote along with your estimated timeline for completing these three milestones.