Context
Millions of Latin American professionals have intermediate English that never improves: they understand, but they don’t practice real conversation. Lenguas solves that with Lía, an AI coach that talks with them by voice, corrects them and tracks their progress.
Problem
A voice conversation with AI demands minimal latency: if the answer lags, the illusion of conversation breaks. A good coach also needs memory — remembering the student’s mistakes and adapting the next session.
Solution
- Real-time bidirectional audio with the Gemini Live API: the student speaks and Lía answers with voice, with natural interruptions.
- Reasoning and memory with Claude: session analysis, error-pattern detection and planning of the next practice.
- A complete product, not a demo: auth and data on Supabase, subscriptions with Stripe, product analytics with PostHog and 3D visuals with Three.js.
Results
Deployed and running at lenguas.co, with onboarding, phased practice sessions and a progress dashboard.
Built for a client: the code is not public.