Portfolio · Cologne, Germany

Karin Hoehne

Software Developer · AI Engineering

Product designer turned software architect and AI engineer, with 25+ years of experience across design, software, data, and information.

01 · Profile

Design thinking, engineering discipline

Location
Cologne, Germany
Experience
25+ years
Current
Science Media Center Germany
GitHub
zushicat

My background combines design thinking with software engineering, covering software development, data engineering, semantic technologies, knowledge graphs, AI and machine learning.

I work on complex technical problems where different disciplines need to come together: software architecture, data and knowledge modelling, AI/ML, information architecture and user-facing applications. My goal in this work has always been to make complex information and capabilities easier to understand, use and work with.

02 · Focus

Current areas of focus

  1. 01Generative AI and LLM-based systems, including RAG, AI agents, prompt and workflow design
  2. 02Knowledge engineering, semantic technologies and knowledge graphs
  3. 03Search and retrieval across structured and unstructured data
  4. 04Database systems and data architecture
  5. 05Software architecture for complex applications
  6. 06AI-powered tools and interfaces
  7. 07Product design, UI/UX and information architecture

03 · Trajectory

From design to AI engineering

Twenty-five years, four disciplines, one thread: making complex information usable.

  1. 01 1996–2004

    Design

    Where the eye was trained: identity, exhibit and interaction design — print, stage and early web.

    • Computer Game Designer

      calculus Softwareengineering · Freelance Cologne · 1996–1998

      Game design and development at a small Cologne studio.

    • Designer

      Freelance Cologne/Bonn · 1998–2004

      Comprehensive design services across print and digital media.

      • Corporate identities and large-scale event conceptualization
      • 3D modeling, visualization and exhibit design
      • Multimedia applications, video editing and early web development

    Origins 1995 — industrial design at U. Wuppertal · exhibit-design internship at Tetrad Design, Annapolis, MD.

  2. 02 2007–2013

    Digital Humanities

    Research software where semantics meets code: archives, ontologies and digital libraries.

    • Research Associate

      U. Cologne · Institute of Digital Humanities (HKI) · Full-time Cologne · 2007–2009

      Digital-library infrastructure for manuscript and copyright-history collections — ENRICH and “Primary Sources on Copyright History”.

      • Browser-based content management for contributing authors; backend XML database implementation
      • Schema conversion to Dublin Core and TEI P5 via XSLT; OAI-PMH interfaces
      • Frontend concept and design
    • Lecturer

      U. Cologne · Part-time Cologne · 2007–2010

      Practical exercises in C++; introductory programming courses in Processing/Java; faculty tutorials.

    • Research Associate

      U. Cologne · CoDArchLab, Institute of Archaeology · Full-time Cologne · 2009–2011

      Core development on the Arachne archaeological database, incl. the Hellespont project integrating Arachne and Perseus.

      • LAMP-based core system contributions
      • Standard schemas and ontologies — Dublin Core, CIDOC CRM, METS/MODS — for data transfer and aggregation
      • Prototyped applications on those interfaces
    • Software Developer

      Cambridge Faculty of Law · Freelance Cambridge, UK · 2011–2013

      Rebuilt the digital archive “Primary Sources on Copyright History (1450–1900)” — see Selected work.

  3. 03 2012–2019

    Data Engineering

    Production data work at scale: pipelines, knowledge graphs and interfaces people could actually use.

    • Software Developer

      HRG · Freelance Cologne · 2012–2015

      REST interfaces for bidirectional data transfer between travel booking systems, plus import-validation monitoring with a browser-based interface.

    • Software Developer

      Heimkomfort · Freelance Cologne · 2013–2015

      Complete retail infrastructure for an online commerce business on Magento — owned end to end, platform to DevOps.

      • Self-managed open-source web stack, from setup through production operation
      • Custom platform modules and browser-based back-office tools
      • Database administration, DevOps and continuous maintenance
    • Software Engineering | Data Engineering

      fedger.io · Full-time Cologne · 2016–2019

      Data-driven products for the hospitality industry.

      • End-to-end ETL/ELT pipelines across relational and non-relational stores
      • Multilingual knowledge graph integrating public linked data with proprietary industry data
      • NLP/ML extracting structure from domain-specific text; data fusion across text, images, point-of-sale, geolocation and social media
      • Interactive web visualizations for non-technical stakeholders
  4. 04 2021–Now

    AI Engineering

    The current chapter: AI engineering for science communication.

    • Software Developer | AI Engineering

      Science Media Center Germany · Full-time Cologne · Jan 2021 – present
      Augmented Science Journalism 2021–2023

      Knowledge-graph and AI solutions for editorial content analysis and processing; backend infrastructure, data platforms and APIs.

      • Knowledge graphs grounded in semantic-web standards, integrating editorial content with public linked-data repositories and ontologies
      • LLM infrastructure operated end to end — self-hosted model serving, orchestration, low-code workflow automation
      • Prompt engineering and RAG; type-safe, schema-first APIs; polyglot stores (relational, GraphQL, vector)
      Bridging the Communication Gap 2024–present

      AI-supported science communication with the Faculty of Environment and Natural Resources, U. Freiburg — forestry, environmental and sustainability sciences.

      • Heterogeneous data pipelines — bibliographic records, media, web and full text — with semantic chunking and LLM-assisted classification and retrieval
      • Hybrid semantic search on vector-database infrastructure: embeddings, lexical scoring and neural reranking
      • Multi-agent architectures and MCP tool servers; RAG enrichment services; REST APIs with SSE streaming
      • TypeScript/React frontends for conversational AI, faceted search and monitoring; LLM gateway across self-hosted and commercial models

04 · Selected work

Selected work

Three projects that show the thread: structure the information, then make it usable.

Bridging the Communication Gap

2024–present · Science Media Center Germany × U. Freiburg

AI-supported science communication with the Faculty of Environment and Natural Resources (University of Freiburg), serving forestry, environmental and sustainability sciences.

  • Hybrid semantic search over vector-database infrastructure — embeddings, lexical scoring and neural reranking across data sources
  • LLM-powered enrichment following RAG methodology; multi-agent architectures with tool servers on the Model Context Protocol
  • TypeScript/React frontends for conversational AI, faceted search and monitoring, on token-authenticated REST APIs with SSE streaming

Augmented Science Journalism

2021–2023 · Science Media Center Germany

Knowledge-graph and AI solutions for editorial content analysis and processing — backend infrastructure, data platforms and APIs.

  • Knowledge graphs grounded in semantic-web standards, integrating editorial content with public linked-data repositories and ontologies
  • LLM infrastructure operated end to end, from self-hosted model serving to orchestration and low-code workflow automation
  • Polyglot data infrastructure — relational databases, GraphQL interfaces and vector stores — for hybrid search over structured and unstructured content

Primary Sources on Copyright History, 1450–1900

2007–2009 · 2011–2013 · U. Cologne × Cambridge Faculty of Law

Digital archive of historical copyright documents — conceptualized in Cologne, rebuilt in Cambridge six years later. The archive is still online.

  • Rebuilt system architecture on CouchDB and RESTful principles, with an XML→JSON migration pipeline for legacy data
  • Full-text search with Apache SOLR; OAI-PMH metadata interface on Dublin Core standards
  • Browser-based CMS for research contributors; integrated external sources (Wikipedia, Google Books); URL persistence and permalinks

05 · Toolbox

What I build with

AI & Semantics

  • RAG
  • LLM infrastructure
  • AI agents
  • MCP
  • Prompt & workflow design
  • Knowledge graphs
  • Semantic web
  • Ontologies
  • NLP
  • Hybrid search

Data & Backend

  • REST APIs
  • GraphQL
  • Vector databases
  • ETL/ELT
  • CouchDB
  • Apache SOLR
  • XML · XSLT
  • OAI-PMH
  • Dublin Core
  • CIDOC CRM
  • TEI P5
  • Containers · CI/CD

Frontend & Design

  • TypeScript
  • React
  • JavaScript
  • PHP · LAMP
  • Magento
  • UI/UX
  • Information architecture
  • Corporate identity
  • Exhibit design

Skills as named in the work above — nothing aspirational.