Full Stack Engineer

About the role

UniSystems is looking for a senior Full Stack Engineer to join its UniQue team in Brussels. You will help turn digital visions into reality by building AI‑enabled applications that support strategic foresight and policy analysis.

Key responsibilities

• Support software development programmes for digital innovation and technology applications.
• Design and implement advanced application capabilities that enable complex, multi‑step user workflows for analysts.
• Develop full‑stack integrations with AI‑enabled backend services, exposing AI‑driven analytical functions, retrieval mechanisms and automated synthesis.
• Apply sound software design principles to ensure transparent, auditable, and controllable analytical workflows with clear traceability.
• Deliver deployment‑ready solutions that meet strict governance, security and operational constraints.

Required profile

• BSc degree in a relevant field or equivalent higher‑education experience.
• At least 8 years of experience covering frontend and backend development, system architecture, integration and end‑to‑end ownership.
• Extensive knowledge of modern frontend frameworks (Vue.js, React, Astro) and backend frameworks (Python, FastAPI).
• Proven experience integrating frontend applications with high‑volume data ingestion, search, retrieval and analytics back‑ends.
• Practical experience with AI and LLM‑based services, including Retrieval‑Augmented Generation and traceable AI outputs.
• Experience designing analyst‑facing workflows with emphasis on transparency, source traceability and user control.

Required skills

• Vue.js
• React
• Astro
• Python
• FastAPI
• API design and schema validation
• Service orchestration
• High‑volume data ingestion and querying
• Search and retrieval systems
• Analytics backend integration
• AI integration and LLM services
• Retrieval‑Augmented Generation (RAG)