Apache Kafka Experts in Cologne

Jens R.

Technical Product Owner

Kerpen

Last position:

Platform Architect & Senior Developer at Direct client, industrial measurement technology, medium-sized company

Technical leadership across hardware, firmware, and software teams; scope: hardware/firmware team (4 people) and leadership group (5 people)
Consolidated and documented a product family that had grown over more than 15 years and aligned it with CRA compliance — from the bare-metal I/O module to the cloud interface.
Provided the most important customer product with the essential requirements and architecture documentation within two months — for a firmware landscape that had grown over more than 15 years. It now supports the customer’s modernization strategy.
Established a monthly reporting line to the supervisory board and executive board within three months: nine meetings since 12/2025. The report itself is versioned and built from the CI pipeline; it is based on automatically collected activity and release data instead of assessments.
Built a container-based CI/CD infrastructure from scratch: cross-compilation, host tests, and documentation builds in one continuous pipeline.
Introduced declarative QA gates for DevOps and development artifacts — from the start using lefthook instead of pre-commit, executed in a dedicated container image.

Technologies used: arc42, req42, tpo42, docToolchain, PlantUML, ArchiMate, C4 model, ADR, C, C++ (GTest), CMake, Bare Metal (ARM Cortex-M3/M7), OCI containers, Jenkins, lefthook, Prometheus, Grafana, SBOM, CRA, OPC, SCADA, PLC integration, IPv6 migration, Zero Trust, Sociocracy 3.0, Cynefin

Armen M.

Interim CTO | Transformation Leader

Odenthal

Last position:

CTO/CPO Platform & Technology at Green Mobility Holding

Overall responsibility for platform transformation across ERP, CRM, PIM and AI-supported process automation
ERP transformation: Introduction and migration to Microsoft Dynamics 365 Business Central
CRM & Growth Stack: Implementation of HubSpot as the central CRM and platform for lead and marketing automation
Product data & Commerce Enablement: Introduction of an ePIM to scale Category Management and digital Commerce processes
AI-supported process automation: Design and introduction of agent-based AI workflows to automate processes in Business Services, Accounting, Tender Management and Marketing
Building a scalable platform organization consisting of Product Development, DevOps, UX, Cloud Engineering and Corporate IT
Introduction of modern product and portfolio governance (e.g. OKRs, portfolio boards, value-based roadmaps) to manage technology-driven initiatives
Harmonization of heterogeneous system landscapes and transformation into a modular, scalable platform architecture (ERP, CRM, PIM, integrated customer journeys)
Coaching and development of Product Owners, Tech Leads, Delivery Managers and UX teams in building a scalable product organization

Burhan D.

Experienced IT and AI Architect

Niederkassel

Last position:

Enterprise Architect & Solution Architect at DB Netz AG

With project PRIZMA, DB will modernize its infrastructure on the one hand, and develop a fail-safe IT landscape on the other hand, which can be restored quickly and securely in case of a disaster.

Capture current architectures of existing systems as well as methodical consulting and development of target architectures
Deepen and maintain the building plan / target IT landscape
Implement technical architecture concepts & architecture descriptions
Implement migration concepts for updating and further developing the platform and information systems
Assess submitted improvement suggestions as part of the project
Capability management: identify capability gaps, develop target visions, and support transformation planning within the enterprise architecture.
Create a compatibility matrix of the components in use and compare dependencies of specific versions
Create an IT concept for extending the platform with the following topics: hardware and software requirements, security, licensing, high availability, load balancing, backup & recovery, update strategy, monitoring integration, etc.
Coordinate with business architects as well as technical architects from the cross-functional architecture area of the PRISMA program for the topics (backup, Active Directory, monitoring, Citrix, and business applications ...)
Status meetings and alignment of project planning with the Release Train Engineer / Project Manager
Advise the Release Train Engineer / Project Manager in identifying project risks
Advise the System Architect Engineers in steering the implementation of the concept
Implement the IT concept
Document the infrastructure

Label: MS Project, LINUX, Windows, ORACLE, Java, REST, SharePoint, Microsoft Exchange, UML, Enterprise Architect, BPMN, AZURE, AWS, V-MODEL, Micro Service, VisualStudio, SAP S/4HANA, SCRUM(SAFE), ESB (TIBCO), Python, Innovator, LeanIX (TOGAF), Ansible, Ansible Tower, Ansible Automation, ROBOT, SpringBoot

Hassan A.

IT Consultant

Düsseldorf

Last position:

DevOps & Observability Consultant at ALDI South (Albrecht's Discount)

Supporting the DevOps team in Terraform-managed, multi-region AWS infrastructure to achieve environment parity.
Developed end-to-end CI/CD pipelines using AWS CodePipeline, CodeBuild, and CodeDeploy, automating the build and deployment.
Maintained pre- and post-deployment scripts to automate critical tasks such as database schema migrations and environment sanity checks.
Implemented CI/CD flow specifically for hotfixes via separate Git branches, managing back-merge activities from feature branches to release branches to ensure code integrity through automated conflict resolution.
Deployed a dedicated, lightweight sanity check application hosted cost-effectively on Azure Container Apps to run automated health and basic functional checks as a post-deployment activity triggered via pipeline.
Investigated production incidents through code changes and AWS CloudWatch logs.
Coordinated integration of Dynatrace APM and its APIs for monitoring purposes.
Full stack QA strategist for a high-traffic e-commerce platform built on a layered architecture for the back-end testing of core platform services, especially the order management system in Zed and Glue layers.
Managed automation activities, testing process, and refactoring practices.
Responsible for framework migrations, setup, and training for new automation frameworks.
Promoted a shift-left approach within the QA team and created the test concept.
Participated in meetings with IT managers, business owners, product owners, and team members.
Designed and implemented contract testing to validate API schema compatibility between the order management system and the Zed and Glue layers, reducing production-relevant breaking changes by approximately 3%.
Led the migration to a multi-environment framework that enabled test execution across 4 country configurations from a single codebase.
Integrated automated unit and functional tests directly into the GitLab CI/CD pipeline, reducing pipeline runtime by 32%.
Coached and trained 5 QA engineers across Germany and Hungary in test automation, framework architecture, and best practices.
Architected a layered backend test automation framework separating business logic, API request builders, and the database layer.
Piloted AI-assisted testing with Playwright Agents, the Playwright MCP Server, and GitHub Copilot for automated test generation, execution, and self-healing Playwright scripts.

Maurice K.

Senior Solution Architect

Last position:

Solution Architect – Cloud-Native Transformation of IoT Monitoring Platform at NDA / Wind Energy Sector

Led the end-to-end architecture and migration of a legacy on- premise IoT monitoring system to a cloud-native Azure platform within a 17-member development team
Designed and implemented a scalable microservices architecture (Java 21, Spring Boot, Kubernetes, Azure Services), decoupling IoT data streams and eliminating legacy system bottlenecks
Defined technology stack, mentored developers, and orchestrated cross-functional teams in 4 countries to ensure high-quality delivery and alignment with architectural standards
Drove requirements engineering and system redesign, removing years of technical debt and introducing event-driven processing and automated workflows
Key Achievements
Increased system stability and uptime by ~10x, eliminating need for 24/7 DevOps intervention
Reduced hosting costs by ~80% (5x savings) through cloud optimization
Improved performance and scalability, enabling stable handling of high-volume IoT data streams
Delivered successful zero-disruption migration from on-prem to cloud, with strong user satisfaction and reliability from day one

Andreas B.

Senior Software Developer

Troisdorf

Last position:

Senior Software Developer at ELIONOVA AG

Created an application to control measurement hardware with a Tauri application using React.JS and TypeScript on Raspberry Pi
Developed a cloud application for storing and analyzing measurement results using Spring Boot and React.JS
Built a Tauri application for printing ZPL labels on Windows
Technologies: Java, JavaScript, Tauri, Rust, React.JS, AWS, Kubernetes, Docker, GitLab CI/CD, REST API (JSON), Maven, CI/CD, PostgreSQL

Pierre G.

Ansible Automation, Windows Third Level Support

Last position:

Ansible Automation, Windows Third Level Support at DB InfraGO AG

PRISMA project
Ansible automation
Windows third-level support for Windows NT, Windows 2000, Windows 2013, Windows 2016, Windows 2019

Hooman B.

Fullstack Developer

Last position:

Fullstack Developer at Möbel Roller GmbH

Further development of the existing e-commerce platform based on SAP Commerce (Hybris) to meet the growing demands of digital commerce.
Ensuring the scalability and performance of the backend, so the platform remained stable and efficient even under heavy user load.
Development and integration of new OCC REST APIs and services for modular extensions and flexible adjustments, to implement new features quickly.
Optimization of data flows and interfaces, which significantly improved platform efficiency and system performance.
Ensuring a maintainable and scalable code base by using Clean Code principles, proven design patterns, and a future-proof architecture.
Reduction of errors through extensive testing with JUnit, Mockito, and load tests with Gatling, supported by the introduction of automated test processes.
Improved system performance through targeted refactoring measures and efficient database queries, especially to handle peak loads.
Use of modern cloud and monitoring tools such as Kubernetes, Google Cloud Platform (GCP), and Grafana to ensure a stable and monitored infrastructure.
Clear improvement in efficiency, scalability, and reliability of the platform, which now meets the demands of a dynamic and growing e-commerce market.

Stefan M.

Installation Portal Server and Content Management Integration

Köln

Last position:

Bundesrechtsanwaltskammer

Design, planning and execution of complex acceptance tests for a document exchange platform for the German justice authorities.
Validation of decrypted and certificate-based message exchange via web platform, mobile app, and Java API.
Documentation of test cases, execution steps, and test results.
Technologies: Windows 11/10, Ubuntu, iOS, Android, Bash for Windows, Java 17, IntelliJ, Git, Jira, Confluence, Citrix Server, xJustiz standard implementation, specific justice software.

Hamdi R.

Lead Full-Stack Developer & Solution Architect

Bonn

Last position:

Full-Stack AI Developer at Karray-Pflege GmbH

PFS-Matching-App

Integrated an intelligent LLM chatbot using LangChain4j, enabling conversational AI, context-aware question answering, document summarization, and autonomous tool execution.
Implemented Retrieval-Augmented Generation (RAG), prompt engineering, and AI agent workflows to connect large language models with enterprise data and backend services.
Developed RESTful APIs and secure backend services to support AI-driven interactions and business processes

Markus G.

Full Stack Developer

Frechen

Last position:

Full Stack Developer at REWE Digital

A warehouse valuation system was reimplemented using Java, Spring Boot, and Camunda. The backend solution focuses on integration and batch calculations, the frontend on managing formulas and reviewing results.
Java 21
Spring Boot
JPA
Maven
REST
Kafka
PostgreSQL
DB2
Liquibase
Google Cloud Storage
Keycloak
GitLab CI/CD
Helm
Terragrunt
SonarQube
Angular
IntelliJ
JUnit 5
Mockito
Open API

Christian H.

Developer

Bonn

Last position:

Developer at Opereon Consulting GmbH

Developed a shop website
Integrated an AI language model
Developed tools for AI-powered webhooks
Technical tools: REACT.js; Elevenlabs; MCP; n8n; HTTP

Jens H.

#52 Test Manager in Safety-Critical Infrastructure

Köln

Last position:

#52 Test Manager in Safety-Critical Infrastructure at Telecommunications Company

Network elements, network, operational and operator-related systems
Supporting around 20 different products (managed agile)
Requirements analysis and management (functional and non-functional)
Test concept and planning (scope, test phases, effort, schedule, resources, organization, etc.)
Aligning approach with clients and service providers
Managing and assisting in creation of test cases for system, integration and end-to-end tests
Guiding and supporting test execution
Defect management and planning bug fixes with external providers
Preparing and facilitating workshops
Regular reporting and creating automated test reports
Further development of agile testing methodology and configuration of supporting tools
Conceptual support in developing a quality seal for rating product and service quality of internal and external providers
Requirements engineering based on ISO/IEC 25010, Scrum, SaFE
BMC Remedy, Atlassian Confluence, Atlassian Jira (including plugins Xray, Structure), Microsoft Office (incl. Visio), Obsidian, doxis document management system, Gitlab, Obsidian

Alexander V.

Software Architect / Software Engineer / Tech Lead

Last position:

Senior DevOps / Platform Engineer at Kaufland e-commerce / real.digital (ex hitmeister.de)

Evolved the platform from bare-metal infrastructure with a monolithic PHP application to a hybrid Google Cloud architecture with Go microservices on Kubernetes
Managed and scaled a production infrastructure with 300+ VMs and dozens of clusters, including MySQL, PostgreSQL, MongoDB, RabbitMQ, Redis and Elasticsearch clusters
Designed architecture, deployment, monitoring, performance analysis, and upgrades for all platform services using Terraform and Ansible
Migrated observability systems from ELK and Prometheus to Datadog, managed with Terraform
Introduced Jenkins CI/CD with SonarQube integration and automated tests to speed up feedback cycles
Containerized the testing environment and implemented GitLab CI pipelines for Docker image builds, static code analysis, and infrastructure tests
Performed zero-downtime migrations of MySQL and MongoDB clusters to Google Cloud
Developed reusable Ansible roles for database clusters and automated data obfuscation for staging environments
Decomposed monolithic databases and migrated to microservice architectures
Built tools to detect and optimize slow queries in MySQL and MongoDB
Conducted online schema migrations with pt-online-schema-change without downtime windows
Developed internal Go applications for batch queries, GitLab-Jira integration, and MongoDB backup recovery
Technologies: Debian, Ubuntu, Alpine, Go, Bash, Python, PHP, SQL, GitLab CI, Jenkins, Drone CI, MySQL, MongoDB, PostgreSQL, Redis, Elasticsearch, RabbitMQ, Kafka, Docker, Kubernetes, Nomad, Ansible, Terraform, Grafana, ELK, Prometheus, Datadog, Nagios, Zabbix, Nginx, HAProxy, Vault, Helm, SonarQube, Filebeat, Auditbeat, Google Cloud, AWS

Peter B.