Senior Python AI Full-Stack Developer / AI Engineer

We are seeking a high-performing Senior Python Full-Stack Developer / AI Engineer to join the development of an innovative, advanced multimodal AI coaching and virtual therapy platform. The project is designed to help couples improve relationships and communication by utilizing a deterministic state-machine approach based on predefined behavioral and therapy protocols. This is a long-term, full-time engagement in an early-stage startup environment, offering high stability and the opportunity to heavily influence the AI architecture of a cutting-edge product.

Responsibilities
Develop, scale, and enhance the core AI microservice.
Build and optimize complex LLM orchestration workflows and LangGraph-based multi-protocol conversation workflows.
Implement deterministic AI conversation flows mapped directly to predefined psychological frameworks and therapy protocols.
Design, maintain, and optimize RAG architecture and long-term memory systems utilizing Pinecone and vector search mechanisms.
Build and scale multimodal AI capabilities, including text, voice, and video processing pipelines.
Optimize token usage, monitor infrastructure costs, and evaluate various LLM providers (Claude, OpenAI, Gemini).
Collaborate closely with founders, backend developers, and behavioral experts to translate therapy logic into machine-executable workflows.

Qualifications
5+ years of professional software engineering experience.
3+ years of hands-on experience building LLM-based systems, production-ready AI applications, and Conversational AI / Chatbots.
Deep commercial expertise in Python, FastAPI, Prompt Engineering, and Vector Databases (Pinecone).
Strong experience with LangGraph, AI Agents, and advanced workflow orchestration.
Proven track record with Multimodal AI (integrating text, audio, and video formats).
Strong understanding of token optimization and cost-efficient AI infrastructure.
Excellent English communication skills (very good verbal and written level).
Nice to Have: Experience with coaching, therapy, psychology, or behavioral AI applications; experience with deterministic AI workflows; hands-on knowledge of audio/video processing pipelines.

Location & Logistics
Location: Remote (Poladn)
Time Zone: CET
Engagement: Full-time (40 hours per week) 1-2 months to begin with and long-term potential.