Building Kindred: A Children's Friendship Book Powered by Google AI

I built Kindred for a Google AI hackathon, and it turned into one of the most technically interesting — and emotionally rewarding — projects I've worked on. The concept: a living digital friendship book for kids (ages 4–12). A child does a voice interview with an AI, gets a personalized illustrated avatar, connects with friends via invite codes, and together they record illustrated story memories. Each story gets an AI-generated scene image, an audio narration, an optionally a video, and requires a parent to solve a math problem before it's shared. Here's how I built it with Google AI models and Firebase. The Stack at a Glance React 19 + TypeScript + Vite 6 + Tailwind CSS v4 — frontend Firebase (Firestore, Auth via Google Sign-in, Storage, Cloud Functions) — backend @google/genai SDK — every AI feature motion/react — animations throughout The key insight driving the architecture: all Gemini API calls go through Firebase Cloud Functions , never directly from the browser. This keeps the