Event Sourcing Experts in Germany

• Build and operate an end-to-end MLOps platform on Azure ML and Kubernetes (Kubeflow) for the automated deployment, monitoring, and scaling of forecasting models (including Temporal Fusion Transformer, Informer, Autoformer).
• Implement CI/CD pipelines in Azure DevOps for the full ML lifecycle – from resource provisioning (Terraform), data transformation (Hugging Face Datasets, Pandas, PyTorch, CUDA cluster) through training and evaluation to model registry and endpoint deployment.
• Integrate MLflow for experiment tracking, model versioning, performance monitoring, and automated registration in the Azure Model Registry.
• Develop and containerize PyTorch training jobs (Azure Notebook, Jupyter Notebooks) for price and time series forecasting (PFC models) with automatic rollout via Azure ML Endpoints and REST/gRPC interfaces, Docker containerization, secured with OAuth 2.0.
• Set up monitoring and alerting mechanisms (Prometheus, MLflow Metrics), log centralization, and cost monitoring.
• Automate infrastructure provisioning and model deployment using Terraform, Helm, and Azure CLI; connect to existing market data systems and event pipelines.
• Migrate existing workloads and databases (IONOS → Azure, MongoDB) with integration into central MLOps workflows and internal networks.
• Extend the platform with LLM-based tools (LangChain, LangServe) to integrate GPT-based analysis modules into existing Spring Boot services for market anomaly detection and automated reports.
• Analyze and architect a software solution to process large volumes of data efficiently (>3000 messages/sec.) (market data store).
• Spring Boot / Java 21 container development with RabbitMQ for distributing stock market data via MongoDB (Kubernetes) with fast storage of data in Redis RMaps, deduplication, forwarding messages to Read Model queues, and building Read Models for UI display in MongoDB.
• Integration of RESTHeart to create a REST API for MongoDB.
• Build an Angular frontend to simplify data queries and master data maintenance.
• Agentic coding with remote and local LLMs (Claude Sonnet, Ollama Qwen) and MCP servers.
• Develop Python scripts for transforming and cleaning incoming stock market data (Pandas, scikit-learn).

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.

• Definition of the software architecture
• Design and development of modules
• Supporting internal employees in the learning and onboarding process
• Tools: SAP CAP / CDS, Java 21, SAP Hana, SAP Business Technology Platform (BTP)

• Introduction of Agile-CCPM in an IT project agency with a focus on PHP-based content management systems.
• Preparation and facilitation of workshops to establish a cross-agency multi-project management system.
• Coordination and support of the agency partners.
• Coaching of the methodological framework.
• Collection, evaluation, and use of organizational metrics to plan next steps.
• Environment: OKR, CCPM, Agile Coaching, Agile Planning, Agile Metrics, Workshops, Facilitation, Change Management, JIRA, Zoom, Slack, Miro.

• Implementing applications with Kotlin and Ktor as microservices
• Using MongoDB in the MongoDB Atlas cloud
• Asynchronous communication of services via Google Pub/Sub
• Using Kotest and MockK for unit tests
• Developing an administration frontend with TypeScript, React and Express.js
• Provisioning environments in GCP using Terraform
• Implementing CI/CD processes with GitHub Actions
• Operating scalable production and test environments in GCP with Kubernetes, Helm and Flux CD
• Monitoring environments with Prometheus and Grafana
• Providing BI data in the Google BigQuery data warehouse

• Architecture and implementation of a fully digitalized closing flow for managing securities contracts within the DVAG infrastructure. The platform aims for maximum user-friendliness, modular extensibility and compliant handling of sensitive data.

• Implementation of a reactive UI structure with a focus on user guidance & accessibility.

• Dynamic control of form and closing processes including validation logic.

• Reactive state management via SignalStore (signals + selective effects).

• UX optimization through adaptive components and Playwright-based UI tests.

• Backend modularization to connect existing sales and contract logic.

• API stability and DTO design according to Clean Architecture principles.

• Collaboration with domain teams to define technical contracts and service boundaries.

• Management with GitHub.

• Unit tests with Jest, E2E tests with Playwright.

• Code reviews, CI-integrated test execution, iterative refactorings.

• Ensuring high coverage and UI stability in the closing flow.

• Technologies: Angular 18, RxJS, SignalStore, HTML5, SCSS, Spring Boot, Kotlin, REST, OAuth2, Jest, Playwright, Clean Architecture.

• Participated in the gradual modernization of components into cloud-native 12-factor applications.
• Worked closely with the business operations team to eliminate manual processes and resolve several performance bottlenecks.
• Designed and implemented a CI/CD pipeline to increase developer productivity, enforce quality and security checks, and automate product delivery.
• Migrated several components into the OpenShift Kubernetes cluster.
• Built a monitoring stack from scratch with Prometheus and Grafana to monitor services running in OpenShift.
• Developed dashboards in both Grafana and Splunk for operational transparency.
• Implemented an OIDC/OAuth2-based single sign-on (SSO) solution with Keycloak to secure multiple applications.
• Technologies: Java, Spring, Quarkus, Kafka, MySQL, Cassandra, Redis, Spring Data, Hibernate, Docker, Kubernetes, OpenShift, Keycloak, OIDC, OAuth2, Helm, Prometheus, Grafana, Splunk, Spark.

• Project 1: Multi-Tenant SaaS Platform: Data Integration & Pricing Management
• Objective: New development of ELT pipeline (replacement for Java 6 legacy), integration of heterogeneous source systems (CSV, Excel, Email, external DBs), event-sourcing for complete auditability, multi-tenant architecture for tenant-capable data processing
• Challenge: Processing millions of records daily, audit compliance, data isolation between different tenants
• Solution: Stakeholder workshops for requirements analysis, event-driven architecture with Axon Framework and Apache Kafka, AWS services (EC2, S3, Lambda, SQS, API Gateway) for cloud integration, PostgreSQL with tenant-specific schemas for multi-tenant data isolation, REST API design with Spring Boot for external system integrations, comprehensive testing strategy (JUnit, Spring Test, Postman, PACT, ArchUnit)
• Results: ELT performance improved from 30+ min to 1-5 min; 2-3 hours daily saved through workflow automation; 10-20 hours/week saved through event-sourcing auditability; 100% audit compliance; secure multi-tenant data isolation for 10+ tenants
• Project 2: Multi-tenant CRM System Modernization
• Objective: Migration of CRM system (20+ years PHP/MySQL) to Java microservices, Domain-Driven Design implementation, establishment of Test-Driven Development, multi-tenant-capable SaaS architecture for multiple customer tenants
• Challenge: Remodeling complex business logic, no existing test culture, scalable tenant management with data isolation
• Solution: Comprehensive testing strategy (JUnit, Spring Test, Postman, PACT, ArchUnit), multi-tenant architecture with tenant-specific databases, REST API design with Spring Boot for cross-tenant integration, Kubernetes and Docker for container orchestration
• Results: 2× performance improvement; deployment time reduced from 40+ min to 5-7 min; migration without production outages; scalable multi-tenant solution for 15+ customer tenants
• Technologies: Java, Spring Boot 3.x, Angular, Apache Kafka, AWS (EC2, S3, Lambda, SQS, API Gateway), PostgreSQL, Axon Framework, Kubernetes, Docker, GitLab CI, REST API

• Provide the Price Listing Service Team Price for all cars and vans in different markets
• Adjust market-specific requirements like taxes, government subsidies, campaigns
• Import, synchronize and store new prices for all new and existing cars in Redis datastore
• Support our product and handle on-call duties
• Daily operations, developing new features, bug fixing
• Pair programming, code reviews, mob programming
• Develop POCs for new ideas
• Maintain and extend the backend
• DevOps tasks
• Perform Kubernetes updates
• Adjust and further develop Kubernetes resources
• Develop and customize Helm charts
• Adjust and update ArgoCD
• Maintain, adjust and further develop CI/CD pipelines

• Fixing issues in the application logic

• Covering the changes with component tests

• Analyzing and documenting the data structure of the different applications

• Analyzing and documenting the parameters for configuring the applications

• Analyzing and documenting the necessary measures to ensure the operation of the applications

• Analyzing and designing the separation of the individual database structures

• Analyzing and estimating the effort for planned enhancements

• Analysis, maintenance and documentation of a heterogeneous legacy system landscape for a print media service provider

• Technology: C#, VB.NET, C, Python, Microsoft SQL Server, Visual Studio 2010, JetBrains Rider, Visual Studio Code, arc42, Draw.io, Jira, GitLab

• Development of a new innovative payment product for the European market with the aim of establishing an alternative to the existing global players.
• Set-up and scaling of the software development processes and teams.
• Architect and implementation of the business processes in an event sourcing microservice architecture.
• Implementation on a prototype in the context of the Digital Euro.
• Technologies: Ktor (Kotlin), AWS Managed Kubernetes with Fargate, MongoDB, React, ElasticSearch, KoTest, Gradle, Agile Development, Pair Programming, GitHub Actions, Gradle, SonarQube

• Co-authored enterprise cloud strategy including security and governance frameworks for 5 subsidiaries, and implemented part of the governance automation.
• Performed regular cloud cost optimization reviews across 10 teams resulting in ~20% cost reduction.
• Led the technology selection for the migration of in-house CIAM for 25M+ accounts to a SaaS solution, and worked with the product team through the migration.
• Supervised the technology selection and designed the architecture and delivery pipelines for the multi-tenant digital news and sports publishing platform, enabling ~250 editors within ~6 months of development start.
• Led the implementation of a multi-brand design system from idea and technical concept to implementation and rollout, enabling rapid UI prototyping for new products in a matter of hours.
• Managed a team of 4 architects and accelerated the professional growth of team members.
• Technologies: AWS cloud, Microservices, Docker, Python, Kafka, JavaScript, TypeScript, React.js, Node.js, GraphQL, REST, Gitlab CI, Visual Studio Code, git.

• Technical Leadership & SW Architecture: Conducting trade-off analyses for technology stacks and leading the design and implementation of the software architecture, including mobile and backend solutions. Facilitating Event Storming workshops for DDD and software architecture.
• Strategic Direction & Organizational Development: Playing a key role in defining the strategic direction of the product and organization, exploring new models such as steward ownership.
• Lean Startup & Agile Development: Introducing Lean and Agile principles, implementing lean prototypes, and ensuring adherence to Lean Startup processes, iterative development from product/solution fit to product/market fit.
• Team Building & Collaboration: Facilitating workshops, retrospectives and future workshops to collaboratively develop tactics and strategies.
• Technologies: Flutter, JS/TS, React, Google Cloud, Firebase, Android, iOS.
• Organizational Methods: Lean startup, lean canvas, lean agile, event storming, retrospectives.

• Leading an eight-member team with a focus on actively promoting an agile mindset
• Supporting the introduction of Scrum within the team
• Planning, designing, and implementing the macro architecture of a distributed system landscape
• Documenting self-contained systems, microservices, and legacy applications
• Integrating third-party software components
• Special attention to scalability and reliability
• Ensuring traceable processes through event sourcing
• Developing multiple ASP.NET and Blazor applications in C# using .NET 5 to 8
• Applying strategic methods from Domain-Driven Design (DDD)
• Decoupling modules using the Mediator pattern (MediatR) and CQRS
• Continuously ensuring code quality through Test-Driven Development (TDD)
• Conducting code reviews via pull requests and pair programming
• Optimizing data storage and access with MS SQL Server, Redis, and EF Core
• Reducing costs and wait times through caching and automatic scaling
• Implementing background jobs using Hangfire
• Developing and integrating REST APIs
• Integrating RabbitMQ and NServiceBus for communication between systems
• Securing various REST APIs and web UIs with OAuth2/SAML/SSO and JWTs
• Developing cross-team technology standards
• Introducing architecture methods in agile teams
• Applying software craftsmanship and Extreme Programming (XP) principles
• Ensuring software quality according to ISO 25010 standards
• Implementing DevSecOps practices
• Migrating various legacy on-premises applications (Azure Stack & IIS) to Azure Cloud
• Modernizing existing application (from .NET Framework 3 & 4)
• Leading containerization with Docker and subsequent migration to Kubernetes
• Introducing and optimizing CI/CD pipelines
• Monitoring production systems using Serilog, Prometheus, Grafana, and Application Insights
• On-call duty and implementing automated error detection
• Analyzing and fixing issues in production as 3rd level support
• Coaching and upskilling working students, interns, and other developers
• Designing and delivering internal training sessions
• Conducting event storming and user story mapping sessions
• Supporting the product owner with technical matters
• Optimizing workflows in Azure DevOps Services
• Requirements engineering in cooperation with relevant business units and domain experts