Stephan Martin-Sabbatical, professional development
Check rate
Experience
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
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
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
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
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
Technical Consultant
Degoya Medienkommunikation oHG
- Design and implementation of a reservation and voucher system for the hospitality industry using MODX, Ext JS, and MySQL
Technical Consultant
GLS
- Design and implementation of interfaces for data migration and system integration using DB2, Siebel, Informix, stored procedures, and shell scripts
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
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
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
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
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
Support
Schlund+Partner AG
- Phone support for hosting products outside business hours
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.
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.
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
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
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
learn.microsoft.com
learn.microsoft.com
Dbt Fundamentals
learn.microsoft.com
learn.microsoft.com
learn.microsoft.com
Scrum Basics
Course by Alexander Kriegisch, Certified ScrumMaster
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Stephan is based in Weinheim, Germany and can operate in on-site, hybrid, and remote work models.
Stephan speaks the following languages: German (Native), English (Advanced).
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 9 months. Note that Stephan may not have shared all experience and actually has more experience.
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.
Stephan's most recent position is Sabbatical, professional development at Self-employed.
In recent years, Stephan has worked for Self-employed, Init AG, and D4L data4life gGmbH.
Stephan is most experienced in industries like Information Technology, Telecommunication, and Transportation. Stephan also has some experience in Government and Administration, Pharmaceutical, and Healthcare.
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.
Stephan has recently worked in industries like Information Technology, Government and Administration, and Healthcare.
Stephan has recently worked in business areas like Business Intelligence, Information Technology, and Research and Development.
Stephan attended Flinders University for Computer Science.
Stephan has 9 certificates. Among them, these include: Google Looker, Snowflake - Hands-On Essentials, and CDVP2 Certified Data Vault 2.0 Practitioner.
The availability of Stephan needs to be confirmed.
Daily rate distribution
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Average rates for similar positions
Rates are based on recent contracts and do not include FRATCH margin.
The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
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 6 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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