Oliver F.-Senior Analytics Software Engineer & Tech Lead
Check rate
Experience
Modernization of a Multi-Company Backend System
Energy utility company
Further development and modernization of a mature Aspire backend application in the energy utility sector, focusing on new business requirements, testing, legacy code cleanup, and stable backend delivery.
Key Contributions & Results Implemented new business requirements in the context of customer orders, subcontractors, and cross-company backend processes, ensuring consistent workflows across a distributed system landscape. Gradually modernized existing backend components and reduced technical debt through targeted legacy code cleanup, refactoring, and structured code reviews. Improved the testability of business-critical services by expanding automated tests with xUnit, AutoFixture, and clearer validation structures. Supported the further development of workflow automation and integration processes through microservices, messaging, and API-based communication. Took over source code from external companies, systematically assessed code quality, and derived technical improvements for maintainability, stability, and integration. Worked in agile development processes with Jira, Confluence, and Azure DevOps and supported cross-team coordination on architecture, quality, and implementation. Technical Metrics Technologies & Methods C#, .NET, ASP.NET, ASP.NET Core, Aspire, Docker, RabbitMQ, gRPC, REST API, Swagger, Microservices, NServiceBus, AutoMapper, Autofac, xUnit, AutoFixture, FluentValidation, Entity Framework Core, MediatR, Redis, Consul, Serilog, SonarQube, Azure DevOps, Azure Monitor, GitLab, Google Protocol Buffers, IronPDF, Mailjet, Jira, Confluence, Miro, Agile Development, Scrum, Code Reviews, Refactoring, Legacy Code Cleanup, Workflow Automation, Power Grids
Legacy System Modernization & Pipeline Automation
Expert and service provider for the chemical industry
Technical consulting and support for a mature legacy software environment in the chemical industry, focusing on code quality, infrastructure improvements, AI-assisted software development, and well-founded architecture decisions.
Key Contributions & Results Acted as a technical sparring partner for architecture decisions in a mature legacy system environment and supported the assessment of technical risks, dependencies, and modernization options. Introduced AI tools for assisted software development and legacy reverse engineering, creating a foundation for faster understanding of historically evolved code areas. Established coding standards and structured review principles to improve maintainability, readability, and long-term code quality. Supported the improvement of automated development and quality assurance processes by analyzing existing workflows and introducing clearer technical standards. Advised on the modernization of legacy code in C# and Visual Basic and helped make technical debt visible and manageable in a targeted way.
Technologies & Methods C#, Visual Basic, Git, GitLab, NUnit, SonarQube, Mistral, AI-assisted software development, Legacy Reverse Engineering, Coding Standards, Code Reviews, Code Quality, Architecture Consulting, Technical Debt, Automated Processes
Senior Analytics Software Engineer & Tech Lead
Optano GmbH
- Took technical responsibility for an existing .NET legacy codebase and improved the sprint delivery rate from ~70 % to >95 % through consistent prioritization of technical debt, clear code ownership, and binding engineering standards
- Established a stable CI/CD pipeline (TeamCity, Docker) and reduced build and deployment times by ~40 % through standardized stages, automated quality gates, and clean dependency management
- Shortened release cycles from quarterly to biweekly, creating a reliable foundation for continuous feature delivery to enterprise customers
- Reduced production errors by 64 % within six months through targeted legacy refactoring, expansion of the test pyramid, and stabilization of business-critical modules
- Increased runtime performance by up to 40 % through decoupling computationally intensive paths, caching strategies, and performance profiling
- Technologies & Methods: C#, .NET, Blazor, ASP.NET (MVC/Web API), CI/CD, TeamCity, Docker, NUnit, Shouldly, Moq, Refactoring, Modularization, Agile Scrum, Performance Optimization, Code Reviews, Security (Keycloak), NuGet, WPF, Technical Debt, Portainer, Docker Swarm, NDepend, Dependency Cleanup, CodeRabbit, Legacy Assessment, Codebase Assessment, MSBuild, Dependency Management, Clean Architecture, Clean Code, Requirements Development, Build Optimization
Senior Software Engineer
Fraunhofer IOSB-INA
- Developed a GenAI prototype for automated AAS creation from technical documents and nameplates, reducing the manual modeling effort from approx. 5 hours to under 15 minutes per AAS
- Restructured the AASX Server and PackageExplorer for production use through clear architecture decisions for six core components and reduced critical runtime errors by around 70 %
- Established an end-to-end CI/CD pipeline with GitHub Actions and shortened release cycles from several weeks to under seven days through automated builds, tests, and analyses
- Measurably increased system performance and reduced startup times by 35 % through modernization of runtime dependencies and optimization of build pipelines
- Sustainably improved code quality through binding coding standards and automated tests, significantly reducing regression-related rework
- Enabled cross-project reusability by defining interoperable AAS and OPC UA data models in industrial projects such as Factory-X and Condition Monitoring
- Technologies & Methods: C#, .NET 8, Blazor, Python, Docker, GitHub Actions, AAS, AASX Server, OPC UA, CI/CD, Automated Testing, Software Architecture, Performance Optimization, NUnit, Strangler Fig Pattern, Dependency Management, DDD, Technical Debt, Code Ownership, Coding Guidelines, Clean Code, Serilog, Incremental Modernization, Breaking changes management, Moq, NDepend, Legacy Assessment, Codebase Assessment, MSBuild, FluentValidation, Modular Monolith, xUnit, Build Optimization
Software Development Mentor
Mentoring Activity
- Supported an aspiring software developer for more than 12 months through successful completion of their training and a clear entry into the profession
- Established a binding learning structure with weekly learning goals and regular mentoring sessions for sustainable skills development
- Accelerated the practical transfer of technical fundamentals through real-world tasks and significantly shortened the familiarization period for new topics
- Supported the transition into the profession through technical preparation and decision-making guidance, avoiding trial-and-error changes
- Technologies & Methods: Software Development, Mentoring, Structured Knowledge Transfer, Problem Analysis, Feedback Processes, C#, Test Pyramid, MSBuild, Clean Code
Senior Software Engineer
Miele & Cie. KG
- Took on the interim role of Technical Product Owner / Tech Lead for a 7-member team across seven release cycles and increased sprint plan completion from ~75 % to >95 % through clear technical prioritization and a focus on technical debt
- Played a key role in modernizing an established .NET codebase (Xamarin → .NET MAUI) for a productive enterprise application with >300,000 monthly active users and reduced app crashes by ~60 % within 12 months
- Established binding clean code rules, architecture guidelines and quality gates across 13 participating teams and increased automated test coverage from ~25 % to >70 %
- Reduced regression-related defects by >50 % through consistent test automation, refactoring and technical consolidation of a codebase with >300,000 LOC
- Reduced technical debt by decoupling critical modules and shortened the integration time for new features from several days to <1 day per module
- Supported data-driven product decisions by introducing analytics for key features and increased their usage by ~30 %
- Accelerated the team's skills development through pair programming and mentoring and halved the onboarding time for new developers from ~6 to <3 weeks
- Technologies & methods: C#, .NET MAUI, Xamarin, ASP.NET-based services, SonarQube, FluentAssertions, Moq, automated testing, refactoring, modularization, quality gates, analytics, pair programming, agile development, .NET 7, NuGet, clean architecture, resilience, DDD, performance profiling, story mapping, root cause analysis, Serilog, legacy assessment, codebase assessment, MSBuild, modular architecture, clean code, requirements development, integration patterns
Senior Software Engineer & Technology Consultant
Salt & Pepper Technology GmbH
- Delivered international cross-platform projects (C#, Xamarin) across more than five product modules and ensured consistent releases in distributed teams
- Reduced regression defects by around 45 % within six months through mocking-based tests, clear acceptance criteria and structured review checklists
- Designed modular architecture concepts for applications with over 100,000 LOC and shortened feature implementation from several days to less than 1–2 days per module
- Advised clients from the consumer electronics and agricultural engineering sectors on architecture and technology decisions and prevented bad investments through early system designs
- Developed internal tools for project coordination and measurably reduced coordination effort and questions between development, QA and product management
- Technologies & methods: C#, Xamarin, mobile cross-platform development, Git, Jira, Bitbucket, automated testing, mocking, software architecture, code reviews, legacy assessment, codebase assessment, NUnit, test pyramid, MSBuild, modular architecture, clean architecture, interface design, clean code, FluentAssertions, SonarQube
Systems Engineer
International Transport Company
- Managed the stable operation of a Microsoft infrastructure for >500 users and ensured system availability of >95 % through structured maintenance windows, monitoring and targeted troubleshooting
- Implemented and maintained Active Directory structures for more than 20 function and role profiles and shortened onboarding and offboarding processes from several hours to <30 minutes
- Increased access security by consolidating, documenting and cleaning up historically grown permissions and reduced security-related support cases by >40 %
- Stabilized Windows server environments through targeted configuration changes, root cause analysis of recurring incidents and sustainable resolution of structural issues
- Created complete system, operations and handover documentation and enabled independent continued operation without external dependencies
- Technologies & methods: Windows Server, Active Directory, Microsoft infrastructure services, identity & access management, monitoring, troubleshooting, system & operations documentation
Research Associate
Trier University of Applied Sciences
- Developed customized software tools (Python, Flask) for research and digitalization projects and reduced manual evaluations from hours to minutes
- Supported more than 20 ongoing research projects by automating data preparation, analysis and prototyping and significantly reduced errors and rework
- Established reproducible analysis pipelines with Python, SQL and MongoDB and increased the traceability of scientific results through versioning
- Served as the technical bridge between research, teaching and IT and shortened coordination and implementation cycles from weeks to a few days
- Enabled students and staff to independently further develop existing software artifacts through workshops and mentoring
- Technologies & methods: Python, Flask, SQL, MongoDB, GitLab, data analysis, workflow automation, reproducible research, Azure DevOps, CI/CD, interface design
Software Engineer Mobile Enterprise Development
DataOne GmbH
- Developed and maintained productive enterprise applications for customer environments and delivered stable releases in short iterations under real operating conditions
- Handled over 100 second-level support cases, systematically analyzed logs and root causes and shortened the average resolution time to <24 hours
- Reduced recurring incidents by ~30 % through sustainable root cause analysis and structural defect resolution
- Worked closely on system integration and data flows between applications and backend systems and ensured consistent, reproducible processes
- Technologies & methods: stabilization of productive systems, error analysis, close support collaboration, system integration, agile development, Azure DevOps, interface design, root cause analysis, observability, technical debt remediation, dependency cleanup, breaking changes management, refactoring
Research Assistant
Hochschule Trier
- Maintained and calibrated measurement and sensor systems for several parallel experimental setups and improved measurement stability through systematic adjustment
- Automated existing measurement and evaluation processes and shortened iteration cycles between measurement and results from days to hours
- Enabled stable long-term measurements over hours to days without technical interruptions
- Analyzed large datasets and prepared results in a structured way for research reports
- Translated experimental requirements into robust, maintainable technical solutions
- Technologies & methods: Automation, system stability, technical analysis, reproducible processes, Breaking changes management, Legacy Assessment, Code Ownership, Coding Style Guides
IT Systems Support & Software Development
Franchise restaurant company
- Ensured the stable operation of the IT and hardware infrastructure across several branch areas and significantly reduced unplanned disruptions to daily operations
- Modernized existing systems and shortened update and adjustment cycles through internal maintenance instead of external dependencies
- Migrated central operational systems to cost-efficient, mobile solutions and reduced hardware costs by >50 %, without affecting ongoing operations
- Implemented technical migrations under production conditions and ensured full functional parity
- Gradually digitized operational processes without interrupting operations
- Technologies & methods: System operations, Legacy modernization during ongoing operations, process digitization, cost optimization, Legacy Assessment, Incremental Modernization, Dependency cleanup
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Education, Manufacturing, Food and Beverage, Agriculture, and Utilities.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, Quality Assurance, Research and Development, and Operations.
Summary
Senior Software Engineer & Tech Lead for .NET legacy modernization with over 14 years of experience in stabilizing and further developing production-critical .NET enterprise systems in industrial and research environments.
My core expertise lies in modernizing existing .NET codebases (C#, .NET Framework→ .NET 6/7/8/9), architecture refactoring, CI/CD stabilization, test automation, and delivering software during ongoing operations. I prefer working in complex brownfield systems where standing still is not an option and technical debt must be reduced in a targeted way.
Demonstrable impact from real-world industrial projects:
- 64 % fewer production errors
- 70 % faster release cycles
400.000 LOC gradually migrated to modern .NET stacks
95 % release stability through robust build, test, and deployment pipelines
Positions at Miele, Salt & Pepper Technology, and Trier University of Applied Sciences, among others – ranging from industrial production systems and large-scale .NET applications to research-oriented software.
I apply Industry 4.0 domain knowledge (e.g. OPC UA, Asset Administration Shell) specifically where it delivers real value for existing systems.
I stand for clear technical decisions, measurable quality, and pragmatic solutions. My focus is on fast stabilization, sustainable architecture, and empowering teams – without over-engineering.
Roles: Senior .NET Engineer | Tech Lead | Interim Architect | Technical Consultant
Focus: .NET legacy modernization, delivery & CI/CD stabilization in industry
Skills
.Net Legacy Modernization
- C# (Expert)
- .Net 6/7/8/9 (Expert)
- Blazor (Expert)
- .Net Maui (Expert)
- Asp.Net (Mvc/Web Api) (Expert)
- Refactoring (Expert)
- Modularization (Expert)
- Nuget Package/Versioning Strategy (Expert)
- Ef Core (Advanced)
- Modular Architecture (Advanced)
- Dependency Management (Advanced)
- Nuget (Advanced)
- Wpf (Advanced)
Architecture & Engineering
- Clean Architecture (Expert)
- Interface Design (Expert)
- Technical Debt (Expert)
- Code Ownership (Expert)
- Coding Style Guides & Guidelines (Expert)
- Clean Code (Expert)
- Requirements Development (Expert)
- Integration Patterns (Advanced)
- Modular Monolith (Advanced)
- Resilience (Advanced)
- Ddd (Intermediate)
- Performance Profiling (Advanced)
- Story Mapping (Intermediate)
Delivery & Quality
- Ci/Cd (Expert)
- Github Actions (Expert)
- Test Pyramid (Expert)
- Xunit (Expert)
- Nunit (Expert)
- Moq (Expert)
- Fluentassertions (Expert)
- Shouldly (Expert)
- Teamcity (Advanced)
- Msbuild (Advanced)
- Build Optimization (Advanced)
- Sonarqube (Advanced)
- Ndepend (Advanced)
- Azure Devops (Intermediate)
- Bitbucket (Intermediate)
- Fluentvalidation (Intermediate)
- Coderabbit (Intermediate)
Platform/Runtime
- Docker (Advanced)
- Root Cause Analysis (Expert)
- Docker Swarm (Advanced)
- Observability (Advanced)
- Serilog (Advanced)
- Portainer (Intermediate)
Modernization
- Legacy Assessment (Expert)
- Codebase Assessment (Expert)
- Strangler Fig Pattern (Expert)
- Incremental Modernization (Expert)
- Dependency Cleanup (Advanced)
- Breaking Changes Management (Advanced)
- Technical Debt Remediation (Advanced)
Data, Platforms & Interfaces
- Sql Server (Advanced)
- Mongodb (Expert)
- Opc Ua (Intermediate)
- Aas (Asset Administration Shell / Verwaltungsschale) (Advanced)
Agile Methods, Roles & Tools
- Scrum (Expert)
- Scrum Master (Advanced)
- Kanban (Expert)
- Agile Software Development (Expert)
- Product Owner (Advanced)
- Tech Lead (Advanced)
Communication, Leadership & Collaboration
- Team Leadership (Intermediate)
- Mentoring (Advanced)
- Pair Programming (Expert)
- Technical Leadership (Advanced)
It Operations, Systems & Support
- User & Rights Management (Advanced)
- Security Fundamentals (Advanced)
- Troubleshooting (Expert)
Research, Automation & Analysis
- Process Automation (Advanced)
- Process Optimization (Expert)
- Data Analysis (Advanced)
Roles & Delivery
- Senior Software Consultant (Expert)
- Tech Lead (Advanced)
- Technical Product Owner (Advanced)
- Dev Ops (Intermediate)
Soft Skills & Additional Competencies
- Technical Leadership & Mentoring
- Pair Programming & Code Reviews As A Learning Method
- Onboarding New Team Members (Halving The Onboarding Time)
- Establishing Engineering Best Practices Across Team Boundaries
- Explaining Technical Concepts Clearly To Business Stakeholders
- Bridging Function Between Development, Qa, And Product Management
- International Team Coordination (Consumer Electronics, Agricultural Technology)
- Systematic Troubleshooting Of Complex Legacy Systems
- Root-Cause Analysis For Sustainable Error Resolution
- Pragmatic Architecture Decisions Without Over-Engineering
Languages
Education
Trier University of Applied Sciences
Master of Science Business Informatics · Business Informatics · Trier, Germany
Trier University of Applied Sciences
Bachelor of Science Computer Science · Computer Science · Trier, Germany
DHC GmbH
IT Specialist for Application Development · Saarbrücken, Germany
Certifications & licenses
Foundational C# With Microsoft
Statistics
Experience
Global experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Oliver is based in Lemgo, Germany.
Oliver speaks the following languages: German (Native), English (Advanced).
Oliver has at least 15 years of experience. During this time, Oliver has worked in at least 11 different roles and for 12 different companies. The average length of individual experience is 1 year and 3 months. Note that Oliver may not have shared all experience and actually has more experience.
Based on recent experience, Oliver would be well-suited for roles such as: Modernization of a Multi-Company Backend System, Legacy System Modernization & Pipeline Automation, Senior Analytics Software Engineer & Tech Lead.
Oliver's most recent position is Modernization of a Multi-Company Backend System at Energy utility company.
In recent years, Oliver has worked for Energy utility company, Expert and service provider for the chemical industry, Optano GmbH, Fraunhofer IOSB-INA, and Mentoring Activity.
Oliver is most experienced in industries like Information Technology, Education, and Manufacturing. Oliver also has some experience in Food and Beverage, Agriculture, and Chemical.
Oliver is most experienced in business areas like Information Technology, Product Development, and Quality Assurance. Oliver also has some experience in Research and Development and Operations.
Oliver has recently worked in industries like Manufacturing, Information Technology, and Chemical.
Oliver has recently worked in business areas like Information Technology, Product Development, and Quality Assurance.
Oliver holds a Master in Business Informatics from Trier University of Applied Sciences and a Bachelor in Computer Science from Trier University of Applied Sciences.
Oliver has 2 certificates. These include: Foundational C# With Microsoft and ISTQB - Certified Tester.
Oliver will be available full-time from January 2027.
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Calculated based on our freelancers’ daily rates as of 26 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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