Stephan Martin - Sabbatical, professional development

Q: Where is Stephan based?

Stephan is based in Weinheim, Germany and can operate in on-site , hybrid , and remote work models.

Q: What languages does Stephan speak?

Stephan speaks the following languages: German (Native), English (Advanced) .

Q: How many years of experience does Stephan have?

Stephan has at least 24 years of experience. During this time, Stephan has worked in at least 12 different roles and for 9 different companies . The average length of individual experience is 2 years and 8 months . Note that Stephan may not have shared all experience and actually has more experience.

Q: What is Stephan's latest experience?

Stephan's most recent position is Sabbatical, professional development at Self-employed .

Q: What companies has Stephan worked for in recent years?

In recent years, Stephan has worked for Self-employed , Init AG , and D4L data4life gGmbH .

Q: Which industries is Stephan most experienced in?

Stephan is most experienced in industries like Information Technology , Telecommunication , and Transportation . Stephan also has some experience in Government and Administration , Pharmaceutical , and Healthcare .

Q: Which business areas is Stephan most experienced in?

Stephan is most experienced in business areas like Information Technology , Business Intelligence , and Project Management . Stephan also has some experience in Customer Service , Research and Development , and Product Development .

Q: Which industries has Stephan worked in recently?

Stephan has recently worked in industries like Information Technology , Government and Administration , and Healthcare .

Q: Which business areas has Stephan worked in recently?

Stephan has recently worked in business areas like Business Intelligence , Information Technology , and Research and Development .

Recommended expert

Weinheim, Germany

Experience

Jan 2024 - Present

2 years 3 months

Sabbatical, professional development

Self-employed

Further training in Snowflake and Google Looker
Working with LLMs: local models (Llama, Mistral, Gemma, Phi, Qwen, DeepSeek, Bitnet, Flux, Whisper), OpenAI API, frontends (ollama, openwebui, loacalai)
Inference methods: llama.cpp, vLLM, transformer
Quantization, benchmarking, prompting
LLM Agents (Tool/Function Calling, LangChain, LangGraph, MCP)
Topics: attention, reasoning, chain of thoughts, RAG, GraphRAG, mlflow
Cloud hosted: ChatGPT, Claude, Gemini

Jan 2022 - Dec 2023

2 years

Berlin, Germany

Data Engineering Architect / Data Analyst / Data Engineer

Init AG

Analyze requirements, design and data modeling
Development, testing and documentation
Operation, maintenance and optimization of data processes
Reporting and requesting changes
Agile approach

Projects:

Archiving EPPSG applications and processes (06/2023–12/2023): testing 2.8 million PDF files (Python), data quality control, archiving, indexing, reporting, delivery
Reporting for the one-time energy price allowance for students (01/2023–06/2023): data modeling and analysis, bug reports, report development, JSON generation for dashboards
Reports for final settlement of the Corona emergency aid (09/2022–03/2023): analysis of existing Excel reports and Freemarker templates, data mapping, creating templates to generate SQL and Excel data
Reports for processing logs of the KONSENS mediation process (01/2022–05/2022): importing, converting and preparing data, linking with Pega data, creating CSV reports

Jul 2021 - Dec 2021

6 months

Berlin, Germany

Data Engineer

D4L data4life gGmbH

Connecting BI event data and mapping JSON data
Building and maintaining the data model
Replacing a database with BI events as the data source
Designing, implementing and testing Airflow DAGs
Coordination with backend developers, data analysis, documentation and database optimization

Technologies: Confluence, Jira, Slack, Google Workspace, GitHub, Docker/Kubernetes, PostgreSQL, Airflow, Python, Metabase

Apr 2018 - Mar 2020

2 years

Frankfurt, Germany

Data Engineer

DB Analytics (Deutsche Bahn)

Designing, implementing and maintaining a datamart including ETL to analyze energy savings of DB Cargo
Comparing data quality of IoT devices from different manufacturers for DB Schenker; providing comparable data for data scientists
Analyzing geodata from IoT devices: stop detection with R and PostGIS, geofencing, migration to AWS Aurora
Designing and implementing a DWH including ETL for line operations analyses of DB Schenker

Technologies: AWS EC2, S3, Aurora, PostgreSQL, PostGIS, MS SQL, 3NF modeling, GitLab, Docker, Python, Bash, SQL, PL/pgSQL, R, REST, JSON, CSV, Confluence, Jira, Slack, MS Teams

Nov 2015 - Oct 2017

2 years

Leverkusen, Germany

Technical Project Manager / IT Engineer

Bayer Business Services GmbH

Development of a tool for MS SQL licensing (PowerShell, MS SQL, Excel)
Implementation of PAM and IAM roles with a least-privilege approach and proof of concept
Analysis of IAM and PAM processes, reporting on MSSQL logins and permissions
Database transition: analysis, planning, creation of guidelines and scripts, managing the migration to ESX clusters
SQL lifecycle management: lifecycle analysis, reporting, guidelines, scripts, change management according to corporate policies

Feb 2015 - Jul 2015

6 months

Viernheim, Germany

Technical Consultant

Degoya Medienkommunikation oHG

Design and implementation of a reservation and voucher system for the hospitality industry using MODX, Ext JS, and MySQL

Nov 2013 - Apr 2014

6 months

Neuenstein, Germany

Technical Consultant

GLS

Design and implementation of interfaces for data migration and system integration using DB2, Siebel, Informix, stored procedures, and shell scripts

Jan 2010 - Apr 2012

2 years 4 months

Business Intelligence Architect – Customer Care

1&1 Internet AG

Responsible for BI strategy and KPI development, and integration of new data sources
Requirements management, design of data models and ETL processes, and data analysis for project control
Projects: integration of the SABIO knowledge management system into the data warehouse, design of near-real-time reporting, evaluation of Talend and Pentaho Kettle as ETL solutions

Apr 2008 - Dec 2009

1 year 9 months

Head of Business Intelligence – Customer Care

1&1 Internet AG

Established and led the BI department for Customer Care (6 team members)
Strategic alignment, integration of new systems, infrastructure expansion, and process and team development
Projects: evaluation of MS SQL Server as a BI solution, implementation of slowly changing dimensions, consolidation of product and organizational dimensions, and preparation for the implementation of MicroStrategy

Apr 2007 - Mar 2008

1 year

Business Intelligence Developer

1&1 Internet AG

Definition, implementation and quality control of performance metrics for support centers
Data analysis for project control and dashboard development using Perl and Excel
Ensuring data availability and quality from InstantOLAP, web front ends, databases, and CSV files

Jul 2002 - Mar 2007

4 years 9 months

Head of Data Management

Schlund+Partner AG

Building and leading the Data Management team (5 people)
Planning and execution of subprojects, resource planning, training and staff meetings
Consulting in process and data modeling
Projects: Internationalization of hosting products, migration of the products for 1&1 and Web.de to a central technical database

Oct 2000 - Jun 2002

1 year 9 months

Developer Data Management

Schlund+Partner AG

Ensuring consistency of technical customer contract data and maintaining rate and contract data
Incident and problem management, process and data modeling, development of a framework for data maintenance
Adapting Schlund+Partner contracts to the 1&1 billing system

Dec 1998 - Oct 2000

1 year 11 months

Support

Schlund+Partner AG

Phone support for hosting products outside business hours

Oct 1997 - Nov 1998

1 year 2 months

Developer

Schlund+Partner AG

Development and support of the "Private Homepages" product
Planning and execution of backups for all Unix servers and workstations

Industry Experience

See where this freelancer has spent most of their professional time.

Experienced in Information Technology, Telecommunication, Transportation, Government and Administration, Pharmaceutical, and Healthcare.

Information Technology

Telecommunication

Transportation

Government and Administration

Pharmaceutical

Healthcare

Business Area Experience

See which departments and functions this freelancer has contributed to most.

Experienced in Information Technology, Business Intelligence, Project Management, Customer Service, Research and Development, and Quality Assurance.

Information Technology

Business Intelligence

Project Management

Customer Service

Research and Development

Quality Assurance

Summary

Over 30 years of experience in IT

solution-oriented, sustainable, analytical, creative

Skills

Industries

Services
Public Administration
Information Technology
Telecommunications
Logistics And Transportation
Chemicals
Pharma
Biotech
Media

Management

Team Leadership
Project Management
Process Management
Process Modeling
Software Engineering
Process Monitoring
Incident And Problem Management

Data: Architecture, Engineering, Management, Business Intelligence

Data Modeling
Data Quality Monitoring
Data Maintenance
Data Migration
Data Analysis
Reporting
Etl
Elt
3nf
Data Vault 2.0
Dimensional Modeling
Apache Airflow
Dbt

Dbms

Postgresql (Oltp, Olap)
Postgis
Amazon Aurora
Microsoft Sql Server (Oltp, Olap)
Sybase Ase
Mysql
Db2
Snowflake (Olap)
Sybase Iq (Olap)

Programming Languages

Python
Sql
Pl/pgsql
Transact Sql
Shell
Powershell
Perl
Javascript
Yaml
Json
Xml

Cloud Computing

Aws Ec2
Aws S3
Aws Aurora
Aws Lambda
Aws Sns
Aws Sqs
Azure
Google

Development

Gitlab
Github
Git
Aws
Azure
Docker
Jupyterlab

Operating Systems

Linux
Microsoft Windows
Mac Os
Android

Office

Jira
Confluence
Ms Teams
Slack
Cisco Webex
Google Workspace
Ms Outlook
Ms Excel
Ms Word
Ms Powerpoint
Ms Onenote
Ms Sharepoint
Ms Project

Languages

German

Native

English

Advanced

Education

Flinders University

Computer Science · Adelaide, Australia

University of Kaiserslautern; Fern University of Hagen

Diploma in Computer Science · Computer Science · Germany

Certifications & licenses

Google Looker

credly.com

Snowflake - Hands-On Essentials

Snowflake

CDVP2 Certified Data Vault 2.0 Practitioner

Course by Michael Olschimke, ScaleFree

AI Fundamentals (AI-900)

learn.microsoft.com

Data Fundamentals (DP-900)

learn.microsoft.com

Dbt Fundamentals

learn.microsoft.com

Microsoft Azure: Fundamentals (AZ-900)

learn.microsoft.com

Microsoft Power Platform Fundamentals (PL 900)

learn.microsoft.com

Scrum Basics

Course by Alexander Kriegisch, Certified ScrumMaster

Statistics

Experience

Total positions 14

Experience in Information Technology 12 y

Avg length 1 y 8 m

Longest experience 4 y 8 m

Global Experience

Countries worked in 1 (Germany)

Primary country Germany

Expertise

Recent roles Sabbatical, professional development, Data Engineering Architect / Data Analyst / Data Engineer, Data Engineer

Main industries Information Technology, Telecommunication, Transportation

Main business areas Information Technology, Business Intelligence, Project Management

Qualifications

Certifications earned 9

Profile

Created

June 2025

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Stephan based?

Stephan is based in Weinheim, Germany and can operate in on-site, hybrid, and remote work models.

What languages does Stephan speak?

Stephan speaks the following languages: German (Native), English (Advanced).

How many years of experience does Stephan have?

Stephan has at least 24 years of experience. During this time, Stephan has worked in at least 12 different roles and for 9 different companies. The average length of individual experience is 2 years and 8 months. Note that Stephan may not have shared all experience and actually has more experience.

What roles would Stephan be best suited for?

Based on recent experience, Stephan would be well-suited for roles such as: Sabbatical, professional development, Data Engineering Architect / Data Analyst / Data Engineer, Data Engineer.

What is Stephan's latest experience?

Stephan's most recent position is Sabbatical, professional development at Self-employed.

What companies has Stephan worked for in recent years?

In recent years, Stephan has worked for Self-employed, Init AG, and D4L data4life gGmbH.

Which industries is Stephan most experienced in?

Stephan is most experienced in industries like Information Technology, Telecommunication, and Transportation. Stephan also has some experience in Government and Administration, Pharmaceutical, and Healthcare.

Which business areas is Stephan most experienced in?

Stephan is most experienced in business areas like Information Technology, Business Intelligence, and Project Management. Stephan also has some experience in Customer Service, Research and Development, and Product Development.

Which industries has Stephan worked in recently?

Stephan has recently worked in industries like Information Technology, Government and Administration, and Healthcare.

Which business areas has Stephan worked in recently?

Stephan has recently worked in business areas like Business Intelligence, Information Technology, and Research and Development.

What is Stephan's education?

Stephan attended Flinders University for Computer Science.

Does Stephan have any certificates?

Stephan has 9 certificates. Among them, these include: Google Looker, Snowflake - Hands-On Essentials, and CDVP2 Certified Data Vault 2.0 Practitioner.

What is the availability of Stephan?

Stephan is immediately available full-time for suitable projects.

What is the rate of Stephan?

Stephan's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.