in-app AI assistant · 2025–26
Tovi — AI Wellness Coach
The conversational AI coach inside StayYoung — answering members' nutrition, fasting, and wellness questions in natural Hebrew, 24/7.
role · Solo build
The problem
Static content doesn't keep people on track — they have questions in the moment. Tovi is the always-available coach that answers in natural Hebrew, right inside the app, instead of sending members off to search.
What I built
- Built the assistant backend on Express + OpenAI — scoped prompts, streaming replies, and guardrails so answers stay on-brand and safe.
- Persisted conversations and context (MongoDB + MySQL) so Tovi can personalise and follow the thread.
- Wired Tovi straight into the member app's chat UI — Hebrew-first, RTL-correct, and fast on mobile.
Impact
- An always-on AI coach handling member questions 24/7, inside the product.
- Production LLM plumbing end to end: prompts, streaming, persistence, and guardrails.