Spring Boot Experts in Hamburg

• Assumed responsibility for backend architecture and technical strategy, planning and leading the platform's evolution in close collaboration with the CTO
• Simultaneously drove the development of new features for the housing and tenant management platform, balancing high-level architectural design with hands-on implementation
• Utilized AI-assisted workflows (with tools such as Claude Code, Codex, Cursor) and worked on AI-based features (with tools such as N8N, Mastra, ElevenLabs)

Technologies: Node.js, TypeScript, React.js, Next.js, PostgreSQL, Google Cloud, Docker, Kubernetes

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.

• 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

• Several projects in a police context
• Model and document police procedures/projects with Archimate (as-is/to-be) in the context of P20 (BKA)
• Create software architectures with microservices
• POC development with Springboot/Docker/Kubernetes
• Project size: 10 people
• Enterprise architecture management with Togaf and Archimate
• Backend software development Springboot
• DevOps with Kubernetes
• Implemented using: Java 17/21, Springboot 3, P20 architecture, Togaf, Archimate

• Independent Software Engineer focusing mainly on complex backend architectures.

• Further development of the compliance products
• Responsible for the Senior Software Engineer role
• Team size: 5 - 15 people
• Tools: TypeScript, Angular 18, Node.js, Nest.js, AWS, Kubernetes/Helm Charts/Docker, GitLab (CD/CI), Elasticsearch, MySQL, OpenAI, Java, RabbitMQ

Fiverr client

• Fixed consumer issues in a production Kafka environment.
• Analyzed consumer lag with Datadog.
• Added synthetic tests to detect issues early.

Stack: Kafka, Datadog, Consumer Groups

• Reviewing functional and technical requirements from a testing perspective
• Creating test cases and automated tests to validate requirements
• Performing manual and automated functional, end-to-end, and regression tests
• Documenting test results and tracking defects
• Using models like GPT-4, BERT, and Hugging Face Transformers for automated test case generation, analysis of test results, and improving test coverage, including bias checks and security reviews
• Techs: MS Office, Jira, Zephyr, Confluence, Tosca, stakeholder communication, Agile, Kanban, Scrum, OpenAI API, Hugging Face, PyTorch, LangChain.

• Remodeling of the system architecture for an Azure-based platform aimed at rapid development of new functionalities
• Modeling of a staging concept for the fulfillment of diverse customer and QA needs
• Creation of requirements for, and oversight of, a proof-of-concept supplier project for a Flutter app with highly advanced BLE functionalities
• Comparison of multiple observability platforms for feasibility and requirements fit within the project environment
• Creation of a mobile app architecture based on domain-driven architecture
• Position of technical advisor and accountable solution architect for two development teams
• Execution of architecture reviews and alignment of changes with architectural expectations
• Skills & Technologies: Microsoft Azure , App Services, NodeJS Mono-repository, microservice architecture, domain driven design, self contained systems, requirements engineering, CI/CD, DevOps, API design, solution architecture

• Prequalified 200 demands within five weeks on the multi-cloud-commerce platform bechtle-clouds.com with three external consultants
• Served a dual role as project manager and requirements engineer for various enhancements
• Domain topics: reimplementation of Entra ID Sync, improvement of support processes, optimizations in the product catalog
• Demand and project management in ServiceNow
• Refinement of epics and stories with internal teams and external service providers
• Management of the external international service provider

• Designed, implemented, and deployed two new microservice components, enabling new business functionalities and supporting regulatory compliance for enterprise clients.
• Ensured business continuity and system reliability within a high-transaction, microservice-based environment, taking ownership of backend systems under dynamic business conditions.
• Identified and refactored inefficient implementations, applying cost-benefit analysis to optimize performance, maintainability, and code quality.

• Integration of SAP Commerce Cloud with SAP Cloud for Customer
• Creation and execution of unit and integration tests
• Error analysis and bug fixing

• Stack: SAP Commerce 2011 (B2C).
• Migrating the data from Stibo system to SAP Commerce Cloud.
• Mapping the data from Stibo system to SAP Commerce Cloud.
• Integrating hot folders to support multiple countries and languages.
• Integrating validation tools for migrated data and generating validation reports.

• Solution for micro-service and frontend solution for the electric grid
• Leading of development teams
• Technologies: React-Native, TypeScript, Kotlin, AWS, Infrastructure As Code, Serverless Architecture, React, NoSQL, GraphQL, Angular, Playwright, Python, ML(Ops), Kubernetes, Docker