Rebuilding a long-running flashcard platform for the AI era
A full-stack rebuild of Braineos, a spaced-repetition flashcard platform, with AI deck generation, subscriptions, an Android app and a connector for AI assistants.
Problem
Braineos started life as a Google App Engine app. Its architecture made it hard to add what learners now expect: AI-assisted card creation, a mobile app, subscriptions and modern sign-in. Existing users and their decks had to come across intact.
What we built
- A new web app on Next.js, tRPC and Prisma, backed by PostgreSQL and Supabase Auth, with a migration that brought legacy users and decks across.
- Spaced-repetition study sessions, public deck discovery ranked by a nightly quality score, and multiple-choice cards.
- Premium AI features: generating decks from notes, suggesting more cards, and fact-checking a deck, with the owner approving every change. Usage is capped by a monthly quota.
- Stripe subscriptions and self-service account deletion.
- An Android app (Expo / React Native) that signs in with Google and studies the same decks.
- A Model Context Protocol connector, so AI assistants such as Claude can create and study decks for a signed-in user.
- Containerized deployment with CI on every merge.
Result
Braineos is live on the web and on Google Play. The same codebase now powers a second learning site, Finance Brain.