AI Engineer with React Native experience

About us:

Our product is a fitness mobile application with AI generation of the fitness plan creation and analization of user’s performance.

The application is developing for iOS and Android, built using React Native and Expo. Our goal is to create a fast, reliable, and scalable user experience while maintaining a simple, pragmatic, and adaptable architecture that is ready for growth.

We intentionally work with a lean stack:

• AI-powered features built with Vercel AI SDK, integrating modern LLM-based workflows directly into the product
• React Native / Expo for cross-platform mobile development
• TypeScript with strict typing and schema-first validation
• Supabase (PostgreSQL, RLS) as a backend platform to minimize custom infrastructure

• Clerk for authentication and identity management

   

About the role:

As an AI Engineer for this health-tech mobile product, you will be responsible for shaping the AI agent and driving production-ready LLM experiences centered around the AI agent. You will work within a modern stack to build reliable services and handle complex data generated for the user avatar.

 

Key Responsibilities

• Advanced Prompt Engineering: You will design complex, dynamic prompt templates with conditional logic to ensure the AI avatar provides high-quality, personalized motivation based on specific user inputs and context.

• Structured Outputs & Schemas: You will design an AI agent in a way to ensure the avatar's health and nutrition advice is predictable and fits the app’s logic.

• Observability & Debugging: Using Langfuse (or similar), you will perform deep debugging of LLM chains to identify bottlenecks and optimize for cost, latency, and context window usage. You will also develop scoring systems to identify and resolve logic errors or hallucinations in the avatar's reasoning.

• AI A/B Testing & Evaluation: You will run systematic experiments via OpenRouter to compare different models and make deployment decisions based on quantitative benchmarks rather than intuition.

Qualifications & Technical Skills

• AI Frameworks: Proven experience with AI SDKs for managing complex workflows.

• Cursor experience is a plus.

• Core Stack: React Native, TypeScript, Supabase, Clerk, Vercel AI SDK.

• Observability Tools: Proficiency in Langfuse (or similar) for tracing, creating test datasets, and integrating real-time feedback scoring.

• Evaluation Methodology: Experience building deterministic validation systems.

• Analytical & Iterative Mindset: The ability to transform raw logs into actionable technical insights and a focus on continuous product improvement.