Software Developers in Hamburg

• 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.

• Lead architect for an enterprise loan digitisation programme, coordinating 12 engineers across five workstreams and serving as final technical authority on system design.
• Cut critical application response times by 68% (display 17.3s → 5.6s; modification 11.8s → 5.0s) through targeted caching, OData query optimisation and lazy-loading refactoring; further optimisation in progress.
• Own production error triage, prioritisation and resolution across a multi-application portfolio supporting live lending operations.
• Design and implement SAP Fiori applications on SAP UI5, TypeScript and RAP, owning delivery from architecture and code through rollout and production support.
• Established C4 architecture documentation and decision records for the full programme, enabling faster onboarding and consistent cross-workstream design governance.
• Co-managed S/4HANA release cycle alongside primary responsibilities, coordinating directly with SAP support to resolve critical system issues across the portfolio.

• 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

• work in the Developer-Experience team to improve developer experience and tooling for all teams of the RTL+ streaming platform
• development of reusable GitLab CI/CD components to standardize processes and automatically enforce code quality and security gates
• infrastructure automation with Pulumi
• operation and monitoring of GitLab Runners in AWS with Kubernetes
• integration and automation of Renovate in GitLab pipelines for continuous dependency updates
• extension of Backstage as the central developer platform to optimize internal workflows and self-service capabilities
• development of various tools and automations in TypeScript, Go, and Python

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.

Project:

• Migration of existing VB6 applications to C# (Web API, web app)
• Report development and risk management systems (C#, API interfaces, databases)
• Document archive (API interfaces, databases)

Team size: 9 people

• Reports for Risk and Credit Management Development and maintenance of report structures to support risk and credit decisions, including data modeling, validation, and automated delivery for business departments.
• Migration and maintenance of a legacy system to the latest version of .NET for the asset management system Planning and execution of the modernization of an existing asset management system, including code refactoring, performance optimization, test automation, and sustainable maintenance after migration.
• Replacement of the COM-based archive connection with a REST API Redevelopment of the connection of the document archive (HYPARCHIV) to a REST API based on OpenAPI/Swagger, including archiving with index and stamp fields as well as PDF export into the customer portal.
• Redesign of payment receipt processing Replacement of an existing Oracle PL/SQL process with a new implementation in C# based on a business concept, including business alignment, data modeling, and test coverage.
• Design and implementation of tests, creation of deployment pipelines, and documentation
• Further development and implementation of change requests.
• Regular code reviews within the team as well as optimization of application scalability and stability

Technologies: C#, .NET 10, ASP.NET, Unit of Work, IoC, Three-Tier Architecture, Entity Framework Core, DB First, Web API, Swagger, OpenAPI, Python, Oracle, HYPARCHIV, Azure, PowerBI, DevOps, AKS (Azure Kubernetes Service), GIT, xUnit, NSubstitute, TypeScript, Vue.js, Pinia,

Methods: agile development using Scrum

• Digital strategy and brand repositioning.
• Website relaunch with UX optimization.
• Digitization of the recruiting process.
• Leadership of cross-functional teams.

• 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.

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

• 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

• Platform: Web.
• Technologies: HTML5, CSS, TypeScript.
• Programming.
• Various updates.

• 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

• Full-stack development of a customizable SaaS platform for the real estate industry
• Running domain discovery processes to gather business requirements and derive technical specifications
• Designing and implementing core features based on a Remix MVC architecture with TypeScript, Node.js, and PostgreSQL
• Focus on usability, extensibility, and high scalability of the platform

• Designed and implemented a Python-based ETL pipeline with the Dagster framework to transform raw energy data from heterogeneous sources using InfluxDB and visualizations in Grafana
• Defined time-based and dependency-based jobs
• Deployed to managed Kubernetes clusters using Helm
• Integrated InfluxDB Cloud
• Prepared data for use in Grafana, including cleaning, normalization, and time-based resampling in Python
• Developed dashboards and visualizations in Grafana
• Developed unit tests with mocking using pytest
• Set up a CI/CD pipeline in GitLab

Technologies: Python, Dagster, InfluxDB, Grafana, pandas, pytest, REST, CI/CD, GitLab, Container, Kubernetes, Helm, Docker, Cloud