Senior Full-Stack Engineers (Python, NLP/RAG) (EU)

About the Project:

Health-tech platform that provides personalized nutrition and lifestyle guidance for cancer patients. It combines medical expertise and artificial intelligence to support people during treatment and recovery. Currently, the client has a small internal team (1–2 engineers) handling maintenance, support, and security patches. The main goal now is to completely re-engineer the backend and prepare the system for a major launch in January 2026with 40,000+ users.

This role involves working independently, taking ownership of the technical direction, and collaborating with the existing team to deliver a scalable, secure, and high-performance backend.

Key Responsibilities:

• Database Overhaul:
  • Fully refactor PostgreSQL database structure and optimize queries for performance and scalability.
• NLP/RAG Optimization:
  • Re-engineer and improve NLP/RAG pipelines to increase speed and reduce costs.
  • Ensure each LLM call uses the most efficient model for its purpose.
• Backend Refactor:
  • Rebuild core backend services using Flask and align them with the new database and AI engine.
• Testing & Stabilization:
  • Thoroughly test the new architecture and ensure platform reliability and security before launch.

Requirements:

• 5+ years of experience as a Full-Stack or Backend Engineer.
• Strong Python and Flask expertise.
• Proven experience in database design, schema refactoring, and query optimization.
• Hands-on experience with NLP/RAG pipelines and LLM optimization.
• Solid understanding of AWS services (Lambda, EventBridge, Docker, RDS).
• English – Upper-Intermediate or higher.

Tech Stack:

• Backend: Python (Flask), SQLAlchemy
• Database: PostgreSQL (AWS RDS)
• Cloud: AWS (Lambda, EventBridge, Docker, QuickSight, Scheduler)
• Integrations: Salesforce, Typeform, Twilio
• Frontend: HTML & JavaScript (no UX/UI work required)