Linux Experts in Hamburg

• Owning RAG, LLM-System, ML-ops-Pipelines for various startups in Insurance, Banking, Energy (KRITIS)

• Administration and further development of the M365 environment, including Teams, Exchange Online, Intune, and SharePoint Online
• Development of dashboards for performance monitoring with Microsoft Power BI
• Implementation of user requirements and processes with low-code/no-code technologies (Power Apps, Power Automate)
• Use of Jira and Azure DevOps to plan and implement user stories in an agile project context
• Participation in daily stand-ups, sprint planning, sprint reviews, and retrospectives as the technical point of contact
• Planning and implementation of security policies using Azure Conditional Access and multi-factor authentication
• Configuration and deployment of clients and applications via MECM (SCCM) and Baramundi

Cloud Journey Kickoff on STACKIT

• Helped the client kickstart their cloud journey on sovereign EU STACKIT platform.
• Bootstrapped IAC & GitOps architecture with Opentofu and ArgoCD.
• Setup platform fundamentals for a fresh, holistic cloud experience: Kubernetes, external secrets, certificate management, gateway API, DNS & routing, observability basics.

• Building a data integration platform for high, medium, and low voltage assets for contextual analysis of time series with master data from the SCADA control system (IEC 60870 104), INIS, and SAP.
• Responsibility for the architecture and implementation of the solution, as well as sparring partner for the Product Owner.
• Use of Kotlin, Spring Boot, Maven, TimescaleDB, PostgreSQL, liquibase, Elements IoT, Docker, Kubernetes, Grafana, Python, jupyter, and various API gateways.

• Onboarded and conducted comprehensive documentation and system analysis to assess the existing data infrastructure, facilitating rapid integration and collaboration across functional data teams (modelling, processing, reporting).
• Collaboratively defined the architecture and project structure for a central data pipeline repository, including hierarchical standards, knowledge management strategies, and role-specific responsibilities, enhancing maintainability and onboarding speed.
• Evaluated and validated open-source data routing tools (Airbyte, Apache NiFi, Dragster) for ingest and sync requirements in retail analytics, including local benchmarking and error-state testing.
• Led the design and deployment of Airbyte in Kubernetes, creating customized Helm charts, securing secrets handling, and configuring Ingress with TLS and internal DNS routing, ensuring full API and UI accessibility.
• Troubleshot and resolved Ingress controller issues, iterating through multiple stages of debugging and testing, and documented setup and replication steps for scalable reuse.
• Mapped data models to ARTS standard, supporting schema alignment for ERP and reporting use cases, and coordinated review loops to align future data processing logic.
• Drafted strategic 1-pagers comparing MinIO, Pub/Sub, and routing architectures, providing technical guidance for architectural decisions and investment planning.
• Enabled secure access and authentication mechanisms, including initial evaluation for SAML integration, cluster-level configuration reviews, and service annotation improvements.

traigo is VTG's digital rail logistics and fleet management platform. It processes large volumes of telemetry, mileage, geofence, sensor and wagon-movement events in near real time and provides operational services for rail logistics customers across Europe.

As part of Team Customer Selfcare, I worked on the design, implementation, optimisation and operation of large-scale backend services and event-driven processing pipelines — covering both feature development and operational ownership of business-critical production systems. I also regularly acted as first responder for production incidents, data inconsistencies and performance investigations across multiple distributed services.

• Design and implementation of event-driven backend services.
• Migration and replacement of legacy processing pipelines.
• Development of replay / rebuild mechanisms for large event datasets.
• High-throughput asynchronous event processing on SNS / SQS.
• Database and query optimisation for PostgreSQL and DynamoDB.
• Design of scalable read / write models and aggregation pipelines.
• Production troubleshooting and operational support.
• Performance tuning and infrastructure scaling.
• Design and stabilisation of integration and system tests.
• Technical concepts, architecture documentation, and cross-team collaboration.
• Support the further development of existing GitLab CI/CD pipelines

Geofence & Wagon Stay Processing

• Algorithm to detect vehicles within geofences (entry, exit, dwell time).
• Event sourcing with guaranteed chronological order within the affected time window.
• Refactored geofence event and wagon-stay processing logic for performance.
• Resolved race conditions and event-ordering problems in distributed services; server-side filtering, aggregation and optimised query pipelines.
• Repair and replay tooling for corrupted or inconsistent movement data.

Fleet Metadata & Mileage

• Modernised the service; migrated storage from DynamoDB to PostgreSQL to improve traceability and accelerate new features.
• Scalable mileage aggregation and replay mechanisms.
• Read / write models and optimised queries for high-volume mileage calculations.

Sensor & Telematics Integration

• Integrated telemetry and sensor processing pipelines.
• Snapshot and state-calculation logic for sensor systems.
• APIs and persistence models for wagon sensor data; data-quality improvements.
• Further development of a service using gRPC for intra-service communication.

Movement Segment Processing & Routing

• Migrated services to new movement-segment event streams.
• Built replay and rebuild tooling for segment correction.
• Optimised throughput and reliability for high-volume event processing.

Condition Monitoring & Wagon Analytics

• APIs and backend services for wagon condition monitoring.
• Brake-wear prediction processing and wagon analytics functionality.
• PostgreSQL views and optimised query models for operational dashboards.

Operational Reliability - First Responder

• Investigated production incidents and distributed-system failures; DLQ analysis, replay and operational recovery.
• Tuned database performance and AWS infrastructure under production load.
• Improved observability, monitoring and operational tooling.
• Supported rollout strategies, monitoring and post-deployment stabilisation.

• Industry: Health Care/ IT
• Tools: Internet, telephone, email, Confluence, Azure DevOps, DISweb, Microsoft Teams, Microsoft Office, FHIR
• Requirements engineering for implementing the e-prescription in an existing PVS and a web-based dialysis monitoring system
• Implementation of the archive and exchange interface of the KBV
• Creation and maintenance of user stories and backlog maintenance
• Stakeholder management and support for developers in implementing the user stories
• Reporting to management and conducting refinements

Self-directed exploration of agentic AI development methods, taken from idea to a working, publicly usable application

• Built an interactive planning tool for modelling retirement withdrawals and tax strategy using an agentic AI (vibe coding) development approach – demonstrating self-directed investigation of new AI-assisted development methods
• Delivered live, tax-aware spending projections and adjustable user inputs; shipped as a free, install-free browser application built in Python, with attention to usability for non-technical users

• Development of a web application for horse betting
• Conversion of the components to script syntax

• Real-time tone detection on FPGA (~20 ms latency target) using a filter bank architecture with a fuzzy-logic decision stage, avoiding FFT due to its window-length/frequency-resolution tradeoff.
• Responsible for system integration and architecture.

• Developing a professional appointment planner for organizations with specific, detailed requirements
• Evaluating various existing software solutions
• Creating a list of technical requirements
• Implementing these requirements
• Technologies under consideration: WebDAV, CalDAV, Rust, Baikal, OAuth, Keycloak

• Environment: AWS, Ruby on Rails, GraphQL, React Native
• Penetration test for Backend, Android-App and iOS-App

• Technical consulting to meet regulatory MiCA requirements for a digital trading platform
• Design and development of backend components and APIs to comply with transparency and auditability requirements
• Optimization of core functions in order execution and market data delivery with a focus on performance and reliability under high load
• Conducting job interviews and structured onboarding of new developers
• Successful and timely implementation of the regulatory MiCA requirements, ensuring uninterrupted operations
• Reduction of user issues and common support requests by fixing complex backend problems
• Strengthening the development team through effective onboarding, mentoring, and knowledge sharing

• Development and further development of e-invoicing solutions, interfaces for invoice processing, and implementation of regulatory requirements

Technology & methods: XRechnung, ZUGFeRD, EN 16931, XML, API integration, backend development, cloud services, automation, compliance, AI-supported document analysis