OPTO · A PERSONAL AI COACH FOR EVERY ASPIRANT
Optima Learn
Opto, a personal AI coach.
For every student.
An AI-native CAT exam-prep platform used by 10K+ students. I lead its engineering: the architecture, Opto (a personal AI coach for every student), the production infrastructure, and the iOS/Android app. Most of the work is the part after the demo: latency, cost, safety, and staying up when traffic does something unexpected.
Visit the platformInside the build Decisions, constraints, and outcomes
A coach that knows the student.
Designed and built Opto end to end: agent architecture, student context, long-term memory, consent-driven actions, safety and evals. The goal is coaching that stays consistent across weeks of preparation. Shipped the experience across web and a React Native app for iOS and Android, including sign-in, in-app purchases and secure token storage.
A conversation that can keep up.
Opto listens and talks back in real time: streaming speech-to-text, a reasoning model and sentence-level text-to-speech over NestJS WebSockets, with barge-in so students can interrupt, and auto-reconnect. Holding one speech stream per session made our vendor’s stream limit the real ceiling, so I moved to per-utterance leases with a Postgres-backed limiter shared across autoscaled Cloud Run instances. That removed a hard 20-concurrent-user limit. Median spoken reply is 2.5 seconds.
Reliable, observable production.
A timed race and immediate status feedback cut worst-case cold-start replies from over 60 seconds to under 20. Traced a crawler surge to database connection-pool limits and rewrote founder-dashboard reporting in SQL, cutting ~190 queries to ~50 per load. End-to-end Langfuse tracing and a per-call cost ledger make voice turns, speech calls and prompts visible, so we can track quality and spend per feature and per student.
.43zk7g3ev6cu9.png&w=3840&q=75)