AI Engineer (LLM/RAG) (m/w/d)

United States Digital Space LLC; Köln; Hybrid; EUR 60.000 - 75.000; Vollzeit

Benefits dieser Stelle

Hybrid office in Cologne

AI implementation growth market

Flexible working hours with overtime

Creativity and freedom to shape proj.

Continuous development and feedback

Team events and workations

Salary from €60,000 gross per year

Zusammenfassung

United States Digital Space LLC in Germany is seeking an experienced AI Engineer to own live LLM pipelines and RAG systems built with TypeScript and Next.js, focusing on reliability, observability and cost efficiency.

This hybrid role offers two Cologne office days per week, collaboration with non‑technical colleagues, and the chance to extend content generation and automated workflows across internal systems.

Qualifikationen

• Production experience with at least one LLM-based system and incident handling.
• Advanced TypeScript and Node.js including strict typing and async patterns.
• Next.js in production with App Router and route handlers.
• Practical retrieval: hybrid search, embedding selection, and reranking.
• Experience processing PDFs, HTML, DOCX with OCR and layout-aware parsing.
• JSON Schema and function calling for structured outputs.
• Experience with LLM evaluation tooling and tracing in TS codebases.
• Familiar with Postgres vector search and cloud platforms.
• English communication; German is a plus.

Aufgaben

• Maintain and improve existing LLM pipelines without production downtime.
• Own the RAG systems end-to-end from ingestion to grounded generation with citations.
• Implement chunk-level access control and tenant isolation across retrieval systems.
• Develop content generation pipelines that deliver high-quality output at volume with human review steps.
• Build automated workflows across ERP, CRM, email and internal APIs with durable execution.
• Establish evaluation framework from production failures and metrics.
• Implement observability across the full request path.
• Optimize cost and latency through caching and model routing.
• Work with non-technical colleagues to specify automated processes.

Kenntnisse

LLM in production

TypeScript

Node.js

Next.js

English communication

German language advantage

Tools

PostgreSQL with vector search

Docker

Git

CI/CD

Azure

OpenAI API

Anthropic API

Jobbeschreibung

For a company in the fast-growing AI implementation market we are looking for an experienced AI Engineer, starting immediately. The company operates LLM-based systems in production: content generation pipelines, retrieval-augmented generation (RAG) over internal documents, and automated workflows deeply integrated with their business systems. The stack is TypeScript and Next.js end to end.

These systems are already live. As AI Engineer you take ownership of them, improve their reliability and quality, and extend them to new use cases. The role combines applied LLM engineering with solid backend engineering in TypeScript. It does not involve training or fine-tuning foundation models.

Stack: TypeScript, Next.js, Node.js, Postgres with pgvector, Docker, Azure, Anthropic and OpenAI APIs, Vercel AI SDK.

Tasks

• Take over and maintain the existing LLM pipelines: assess the current architecture, identify failure modes, prioritise fixes, and refactor and extend without disrupting production
• Own the RAG systems end to end: document ingestion and parsing, chunking, indexing, hybrid retrieval (BM25 and vector), query rewriting, reranking, grounded generation with citations
• Implement and maintain chunk-level access control, index freshness and tenant isolation across retrieval systems
• Develop content generation pipelines that deliver consistent quality at volume, including human review steps
• Build and operate automated workflows against internal and third-party business systems (ERP, CRM, email, internal APIs), with durable and idempotent execution, retry and dead-letter handling, and approval steps for irreversible actions
• Establish an evaluation framework for systems currently running without one: golden datasets derived from observed production failures, retrieval metrics and more
• Implement observability across the full request path
• Optimise cost and latency through prompt caching, batching, model routing and use of smaller models where appropriate
• Assess where deterministic logic is the better solution and implement it accordingly
• Work directly with non-technical colleagues to specify and validate automated processes

Requirements

• Professional experience with at least one LLM-based system in production use, including responsibility for its operation and incident handling
• TypeScript and Node.js at an advanced level: strict typing of non-deterministic model output, async and concurrency patterns, streaming responses, structured error handling
• Next.js in production: App Router, route handlers, server actions, streaming to the client
• Practical retrieval expertise: hybrid search, embedding model selection, cross-encoder reranking, metadata filtering, permission-aware retrieval, and structured diagnosis of poor retrieval quality
• Experience processing real-world documents: PDFs with tables, scanned material, DOCX, HTML, including layout-aware parsing, OCR and evidence-based chunking
• Structured outputs and tool calling as part of your everyday work: JSON Schema, Zod or comparable runtime validation, function calling, handling of malformed or partial output, context window management
• Designed and run LLM evaluations
• Experience with LLM tracing and evaluation tooling in a TypeScript codebase (e.g. Braintrust, Langfuse, Promptfoo, OpenTelemetry or Arize Phoenix)
• Familiar with Postgres including vector search (pgvector or a comparable vector store), Docker, Git, CI/CD and one major cloud platform
• Working experience with the Anthropic and/or OpenAI TypeScript SDKs
• Confident communication in English, German is a plus

If you have experience with any of the following, that's a plus:

• durable workflow execution for long-running, unattended processes (Temporal, Inngest or comparable)
• agent orchestration in production, tool calling, recovery, multi-step workflows (Vercel AI SDK, LangGraph, Mastra, Claude Agent SDK, MCP TypeScript SDK)
• integration experience with enterprise systems such as ERP or CRM platforms like SAP
• security and data protection in LLM systems, prompt injection and data exfiltration defences, PII handling, GDPR-compliant design, EU-hosted or self-hosted inference
• structured or graph-based retrieval for entity-heavy data
• experience migrating live pipelines to a new model, embedding model or index without quality regression
• Azure DevOps, Pipelines, Repos and Boards

Benefits

• Hybrid setup, 2 office days per week in the light-flooded office in the Belgian Quarter in Cologne (with two balconies and the best view over the city ;))
• AI implementation, the growth market of the coming years
• Trust-based working hours with overtime compensation
• Plenty of creative freedom and room for your own ideas
• Continuous development, professional, strategic and technological
• An open feedback culture, transparent communication and short decision paths
• Regular team events and workations
• Salary from €60,000 gross per year, ofc with room upwards depending on your experience

The company is an international team and actively fosters an inclusive environment. Applications from all genders and identities are welcome, regardless of origin, age, religion, sexual orientation or disability. Women are still underrepresented in the tech industry and are explicitly encouraged to apply.