Lennart B.-End-to-End Engineer for AI Systems in Production
Check rate
Experience
Architect / AI Engineer
RTL Group
Editorial AI Agents – GenAI
Media industry
Design and development of an AI-powered multi-agent system for the automated creation and transformation of editorial content. From news articles and teletext to SEO-optimized content with stylistic adaptations tailored to the target format.
- Architecture design and implementation of an Agentic AI system
- Creation and transformation of editorial content for multiple news portals
- Topic Discoverer for classifying incoming news reports
- Rebuilding agent workflows in n8n to enable editorial teams to work with low-code solutions
- Development of monitoring and observability dashboards with Grafana
- Infrastructure as Code and deployment on GKE via GitLab CI/CD
Technologies: Python, Pydantic AI, GCP (GKE, BigQuery, Vertex AI, Cloud Run, PubSub), AWS (Bedrock, SQS), LangGraph, LangFuse, Pydantic AI, n8n, Grafana, Prometheus, GitLab CI/CD, Docker, Kubernetes, Terraform
AI Engineer
auxmoney GmbH
Customer AI Agent – GenAI
Financial industry
Design and development of an AI-powered customer support chatbot with tool use and an FAQ knowledge base – in production.
- Implementation of an Agentic AI system with Strands Agents SDK and Amazon Bedrock AgentCore Runtime
- Development of a RAG pipeline (Ingestion + Retrieval) with ChromaDB as the vector database
- Definition and integration of guardrails for input/output control
- Infrastructure as Code (Terraform) and deployment via GitLab CI/CD
- Monitoring and observability with AWS CloudWatch
Technologies: Python, AWS Bedrock, Strands Agents SDK, MCP, Claude, OpenAI, Parloa, ChromaDB, Terraform, GitLab CI/CD, CloudWatch, Pydantic, Git
Architect / AI Engineer
auxmoney GmbH
Intelligent Document Processing – ML | GenAI | CV
Financial industry
Design, development and production operation of an event-driven service for automatically transforming email attachments into structured target formats.
- Design of an event-driven microservice architecture
- Development and training of a PyTorch CNN model for document classification
- Region-of-Interest Detection for extracting relevant document areas
- Definition of document-type-specific Pydantic schemas as target formats
- Integration of Vision-Language Models (Azure OpenAI, Mistral, Langdock) for schema population
- GDPR-compliant processing and synthetic data generation
- Development of monitoring dashboards including model drift detection and alerting
Technologies: Python, PyTorch, Azure OpenAI, Mistral AI, OpenCV, Pydantic, FastAPI, Kafka, Docker, Presidio, CI/CD, Git, DynamoDB, NewRelic, Langdock
AI Engineer / Machine Learning Engineer
auxmoney GmbH
Intent Detection – ML / GenAI
Financial industry
Production ML service for the automated classification and answering of incoming emails.
- Consulting, design and implementation of ML models for email classification
- LangGraph pipeline for the automatic generation of a fine-grained email taxonomy
- Training of an ensemble model with measurable improvements in Precision and Recall
- Implementation of a RAG system for generating answers from historical email conversations
- GDPR-compliant processing and synthetic data generation
- Monitoring dashboards in New Relic for model drift and alerting
- Model registry and versioning
- A/B testing and canary deployments
Technologies: Python, scikit-learn, LangChain, LangGraph, MLflow, Hugging Face transformers, DVC, Optuna, Pydantic, Docker, Snowflake, Presidio, CI/CD, Kafka, NewRelic, smolagents, Airflow
Architect / AI Engineer
T-Systems International GmbH
AI Operator – RAG / GenAI
Telecommunications
Development and IT architecture consulting for a multi-use-case RAG system on Kubernetes with the following use cases: employee onboarding, Smart Chat and ticket assistance.
- Consulting, design and implementation of RAG strategies with a focus on chat applications
- IT architecture consulting including scaling on Kubernetes (Open Telekom Cloud)
- Creation of evaluation pipelines to optimize RAG hyperparameters
- Processing of multimodal documents from the application management domain
- Research and implementation of state-of-the-art methods in the field of LLMs
Technologies: Python, LlamaIndex, LangChain, Phoenix, MLflow, Ragas, MongoDB, pgvector, vLLM, Llava, Tesseract, Kubernetes, Git
Freelance AI Engineer / Data Scientist
rupcon – Lennart Brentrup IT Consulting
Data Scientist / Cloud Platform Engineer
IT-Dienstleister
Multi-Tenant RAG Chatbot – GenAI / Cloud / MLOps
Development of a multi-tenant RAG chatbot on Azure Kubernetes with secure tenant isolation and centralized identity management.
- Design and development of the Azure Kubernetes architecture
- Integration of Istio Service Mesh for traffic management and mTLS
- Tenant isolation via namespaces, OAuth2-Proxy and Azure Entra ID
- Development of RAG chatbots with access to tenant-specific vector databases
Technologies: Python, Kubernetes, Docker, Istio, Azure OpenAI, Azure Key Vault, Azure Entra ID, LangChain, Streamlit
Data Scientist
Informationsfabrik GmbH
Story Magic – GenAI / Image Generation
Development of a generative AI application for creating personalized and visualized stories for children.
- Integration of the OpenAI, Midjourney and Stable Diffusion APIs
- Prompt engineering to optimize text and image quality
- Development of dynamic prompt templates for consistent story and image generation
- Development of a React app as a user-friendly interface
Technologies: Python, React, LangChain, OpenAI, Stable Diffusion, Midjourney, PostgreSQL, pgvector, Azure
Data Engineer / Data Scientist
Provinzial Versicherung AG
Customer Data Hub – Data Engineering / PySpark
Insurance
Design and development of a company-wide data warehouse for analytics use cases – in productive use.
- DWH modeling and schema design
- Specification and implementation of ETL pipelines (PySpark)
- Automated job and test orchestration with Airflow
- Creation of NBO training datasets and training of recommendation models
- Development of a pipeline for generic customer selection
- Development of a selection tool with PowerBI
Technologies: Python, SQL, PySpark, PyTest, Airflow, Kubeflow, PowerBI, Git
Data Scientist / Machine Learning Engineer
Informationsfabrik GmbH
Next Best Offer Excellence – ML / Recommendation
Development of a generic recommendation system to predict future product purchases.
- Exploratory data analysis and data preparation
- Evaluation of recommendation algorithms
- Creation of training pipelines
- Setup of an MLflow environment for hyperparameter tuning and model versioning
Technologies: Python, Azure, MLflow, PostgreSQL, TensorFlow, LightGBM, Implicit, scikit-learn, DVC, Git, Dataiku
IT Consultant – Data Scientist
Informationsfabrik GmbH
Computer Vision Engineer / Data Scientist
Continental AG
AI Golf-Coaching – Computer Vision / ML
Development of a system that generates movement recommendations for athletes using sensors integrated into clothing and smartphones, as well as object recognition in videos.
- Analysis and preparation of sensor and video data
- Image processing, image classification, and object detection with OpenCV, TensorFlow, PyTorch
- Development of customized training pipelines and model architectures
- Evaluation of the integration of Deep Learning and Gradient Boosting models on mobile devices
- Versioning of model performance and models with DVC and MLflow
Technologies: Python, AWS, SageMaker, TensorFlow, PyTorch, OpenCV, YOLOv5, XGBoost, DVC, MLflow, CI/CD, Git
Data Scientist
WebComputing GmbH
Coovi – Video Training Platform – NLP / ML
Development of a component for the automatic extraction of tags and keywords from presentation media (videos, PowerPoints).
- Requirements engineering
- Implementation and evaluation of various algorithms for keyword extraction (RAKE, TF-IDF, KeyBERT, spaCy)
- Development of customized training and evaluation pipelines
- Development of an API for media delivery and returning results
- UML modeling
Technologies: Python, TensorFlow, spaCy, NLTK, scikit-learn, Docker, Git
Data Scientist / Computer Vision Engineer
WebComputing GmbH
Coovi – Video Training Platform – OCR / Computer Vision
Development of a component for extracting text content from videos and slideshows using OCR.
- Requirements engineering
- Data analysis and data preparation
- UML modeling
- Evaluation of various OCR engines
- Development of an API for OCR integration and returning results
Technologies: Python, Tesseract, OpenCV, PyTorch, scikit-learn, PostgreSQL, Docker, Git
Data Scientist
WebComputing GmbH
Software Engineer
WebComputing GmbH
UDK – Sales Data Classification – Backend / Rule Engine
Development of a Java application for classifying transaction data based on a Rule Engine.
- Implementation of data processing with PostgreSQL and EasyRules
- Containerization and parallelization with Docker
- Development of a user interface with Angular and Flask
Technologies: Java, Python, PostgreSQL, EasyRules, Docker, Angular, Flask, Git
Working Student – Project Management
Hengst SE
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Banking and Finance, Professional Services, Media and Entertainment, Insurance, and Sport.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, Business Intelligence, Project Management, and Research and Development.
Summary
From prototype to production service:
7+ years of experience, 13 projects – including work for T-Systems, Provinzial, Continental, auxmoney and RTL.
From Agentic AI and RAG to classic Machine Learning, Computer Vision and Data Warehousing.
I deliver end-to-end: from architecture to deployment.
Skills
- Ai Engineer
- Llm Development
- Llm-Agents
- Rag Pipelines
- Fine-Tuning (Lora/Peft)
- Evaluation & Data
- Rag Evaluation Pipelines
- Embedding Fine-Tuning
- Machine Learning
- Classic Ml
- Classification & Regression
- Feature Engineering
- Cnns, Rl, Gbdt
- Computer Vision
- Object Detection & Ocr
- Document Classification
- Data Engineer
- Dwh Design & Data Modeling
- Etl & Streaming Pipelines
- Mlops
- Model Deployment & Serving
- Monitoring (Data/Model Drift)
- Ci/Cd Pipelines
Tech Stack
- Languages: Python, Sql, Typescript, Java
- Ml & Genai: Pytorch, Scikit-Learn, Tensorflow, Langchain
- Data & Infra: Pyspark, Kafka, Snowflake, Airflow
- Cloud & Devops: Azure, Aws, Docker, Kubernetes
Languages
Education
FH Münster
Bachelor of Science · Business Informatics · Münster, Germany
Otto von Guericke University
Bachelor of Science · Business Administration · Magdeburg, Germany
Certifications & licenses
Generative AI with Large Language Models (LLMs)
PyTorch Ultimate 2023
Unsupervised & Reinforcement Learning, Recommenders
TensorFlow Developer Certificate
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Lennart is based in Münster, Germany.
Lennart speaks the following languages: German (Native), English (Advanced).
Lennart has at least 7 years of experience. During this time, Lennart has worked in at least 13 different roles and for 10 different companies. The average length of individual experience is 5 months. Note that Lennart may not have shared all experience and actually has more experience.
Based on recent experience, Lennart would be well-suited for roles such as: Architect / AI Engineer, AI Engineer, AI Engineer / Machine Learning Engineer.
Lennart's most recent position is Architect / AI Engineer at RTL Group.
In recent years, Lennart has worked for RTL Group, auxmoney GmbH, T-Systems International GmbH, rupcon – Lennart Brentrup IT Consulting, and IT-Dienstleister.
Lennart is most experienced in industries like Information Technology, Banking and Finance, and Professional Services. Lennart also has some experience in Insurance, Automotive, and Manufacturing.
Lennart is most experienced in business areas like Information Technology, Product Development, and Business Intelligence. Lennart also has some experience in Project Management and Research and Development.
Lennart has recently worked in industries like Information Technology, Banking and Finance, and Professional Services.
Lennart has recently worked in business areas like Information Technology, Product Development, and Business Intelligence.
Lennart holds a Bachelor in Business Informatics from FH Münster and a Bachelor in Business Administration from Otto von Guericke University.
Lennart has 5 certificates. Among them, these include: Azure Fundamentals AZ-900, Generative AI with Large Language Models (LLMs), and PyTorch Ultimate 2023.
Lennart will be available part-time from October 2026.
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Average rates for similar positions
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The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 1 Oct 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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