Freelance Full Stack AI Engineer

About the role

We are partnering with a Germany‑based legal‑tech startup to build a production‑ready platform that automates contract review, clause extraction and compliance checking. As a freelance Full Stack AI Engineer you will design and maintain the API layer that orchestrates calls to large language model services and streams responses to the frontend.

Key responsibilities

• Develop and maintain backend services and REST APIs using Node.js and Express.
• Integrate and orchestrate third‑party LLM APIs (e.g., OpenAI, Anthropic) into product workflows.
• Design and implement real‑time streaming pipelines (WebSockets, Server‑Sent Events) to deliver LLM responses.
• Own technical features from concept through production deployment.
• Collaborate with product and engineering teams to solve customer problems.

Required profile

• Strong commercial experience with Node.js and Express.
• Proven experience integrating LLM APIs such as OpenAI.
• Solid understanding of streaming architectures (WebSockets, SSE).
• Ability to make technical decisions and work independently.
• Familiarity with AI concepts and LLM‑powered product development.

Required skills

• Node.js
• Express
• OpenAI API or similar LLM APIs
• WebSockets
• Server‑Sent Events
• JavaScript

What we offer

• 40 hours per week, fully remote.
• Initial three‑month contract with the possibility of extension.
• Opportunity to work on cutting‑edge AI technology in the legal‑tech sector.