GitLab Experts in Cologne

Halil Oeztoprak

Principal Cloud & DevSecOps Architect (AWS / Azure / Terraform / Kubernetes / CI-CD)

Bonn

Last position:

Senior Cloud Operations & DevSecOps Engineer (Azure / Terraform / CI-CD) at KfW Bankengruppe

Regulated environment within a German banking group (approx. 8,500 employees, hybrid cloud strategy).
Responsible for operating, provisioning, and continuously securing business-critical platforms – including a GenAI chat application, a big data/AI platform, and data science workspaces based on Azure Virtual Desktops and VMs. Ownership of Azure DevOps projects for ShaiHulud and React2Shell, as well as BSI alerts – Security Operations improvements across the SDLC.
Deployment responsibility for the GenAI chat application, big data/AI platform (BDAI), and data science workspaces (AVD/VM-based) in the respective landing zones.
Deployment & release management: end-to-end responsibility for deploying portal and service applications across multiple Azure landing zones, including technical approvals, compliance with development team deployment guidelines, and ensuring ITIL-based change and release processes via ServiceNow.
Azure landing zones & network architecture: design, provisioning, and operation of Azure landing zones for 3-tier web applications with enhanced network segmentation, VNet peering, hub-and-spoke architectures, private endpoints, and firewall integration across separate subscriptions and tenants.
Azure DevOps governance & operations: ownership of the Azure DevOps organization, including projects, repositories, and CI/CD pipelines; implementation of governance requirements such as branch policies, approval gates, permission models, and audit-ready operating structures.
Infrastructure as Code (Terraform): design, implementation, and operation of a modular Terraform architecture for standardized cloud infrastructure deployment, including state management, provider versioning, reusability, and policy-as-code approaches.
CI/CD pipeline engineering: design, operation, and optimization of complex YAML-based CI/CD pipelines with multi-stage deployments, template standardization, self-hosted agents, integrated secret management, and automated quality and security checks.
Git migration & platform consolidation: planning and execution of repository and pipeline migration from Azure DevOps to GitLab CI/CD, including automated scripts, full Git history transfer, pipeline porting, and platform consolidation.
Container & platform operations (AKS): operation and security assessment of containerized workloads on Azure Kubernetes Service, centralization of on-premises container registries for ACR.
OpenShift (OCP) security reviews: security assessment of code baselines, build pipelines, and deployment processes for on-premises OpenShift clusters with critical applications, and derivation of specific hardening recommendations.
Shift-left security & DevSecOps transformation: introduction of a company-wide shift-left approach for early security integration in development and deployment processes, enabling developers to perform self-led security checks and sustainably reduce vulnerabilities before production (IDE integrations, pre-commit hooks, local scanners).
Software supply chain security: analysis and mitigation of supply chain risks in NPM- and Yarn-based applications through dependency audits, CI/CD pipeline hardening, token rotation, and restriction of risky build and lifecycle mechanisms.
Frontend & framework security (React / Next.js): security assessment and coordination of critical vulnerability remediation across platform applications and web frameworks, including coordination and complementary technical mitigations with all teams following BSI alerts.
Software composition analysis (SCA): introduction and operation of automated vulnerability scans for container images, pipelines/artifacts, and third-party dependencies, including SBOM exports within CI/CD pipelines.
SAST/DAST integration: design and piloting of static and dynamic application security tests in close collaboration with security architecture and development teams, for continuous improvement of code and runtime security, and establishing operational acceptance tests.
Artifact & registry consolidation: analysis and consolidation of all package and container repositories for service applications and AKS workloads, aiming for a centralized, secured registry strategy with centralized vulnerability scanning and governance.
Dependency-Track & SBOM strategy: advising the compliance board on introducing a central SBOM and vulnerability management platform to increase enterprise-wide dependency transparency and accelerate CVE response capability.
CI/CD pipeline hardening: security analysis and cleanup of the existing pipeline landscape by removing unused pipelines, improving secrets hygiene, implementing least-privilege principles, and isolating build agent environments.
Azure Web Application Firewall (WAF) optimization: analysis and tuning of existing Azure WAF rules (OWASP Top 10 Core Rule Set, DSR/SDC, custom rules) to defend against known vulnerabilities and exploit patterns, including reducing false positives and improving threat detection.
Documentation & stakeholder communication: creating and maintaining technical documentation, runbooks, and architecture overviews in Jira and Confluence, as well as active knowledge transfer between operations, development, security, and compliance stakeholders.

Christoph Sawicki

Test Manager

Last position:

Test Manager at Logistics

Coordination and planning, execution, documentation, and analysis of test cases
Development of test concepts considering best practices (e.g., test pyramid) with a focus on reliable, automatable test runs
Implementation and maintenance of test cases according to the test concepts
Technologies: Citrix Workspace, Shopify, Jira, Xray, MS Teams, MS SharePoint, Confluence, MS Office 365

Marc Smyk

Fullstack Engineer | Java & Spring Boot | Angular | System Integration

Leverkusen

Last position:

Fullstack Developer at PLANT-MY-TREE

PLANT-MY-TREE®-per-order

The application enables Shopify merchants to automatically place tree-planting orders for every incoming order. By integrating ecological contributions directly into the purchase process, the manual effort for tracking and billing reforestation initiatives is eliminated. The system increases transparency for end customers through real-time visualizations of the ecological impact directly in the storefront. The architecture is based on a modular monolith with Spring Boot in the backend and an integrated React app inside the Shopify admin area. The solution uses webhooks to capture order data in an event-driven way and integrates the weclapp ERP system for automated monthly invoicing. An app proxy mechanism provides dynamic statistics such as CO2 compensation and planted trees without any performance loss for the merchant shop.

Tasks:

Design of the modular software architecture based on Spring Modulith to ensure high maintainability
Development of the event-driven business logic for evaluating Shopify orders via webhooks
Implementation of automated invoicing by connecting the weclapp REST API
Building the frontend using React Router and Shopify App Bridge for native integration
Design of the database model and implementation of the persistence layer with JPA/Hibernate and Prisma
Integration of internationalization processes for global use in the frontend and email communication
Automation of deployment processes using Docker and GitLab CI/CD

Project skills: Java 25, Spring Boot, Spring Security, Spring Modulith, Hibernate, JPA, REST API, PostgreSQL, Maven, Liquibase, React, TypeScript, React Router, Vite, Node.js, Prisma, Zod, Docker, Docker Compose, GitLab CI/CD, Shopify CLI, Shopify App Bridge, Polaris, weclapp, i18next, Lombok, Vitest

Rodion Orlinskiy

Founder, CTO & Managing Director

Bonn

Last position:

Founder, CTO & Managing Director at MYNR Product Mining GmbH

Responsible for the architecture and development of an AI-native SaaS platform for industrial product portfolio management.
Designed the modern data platform architecture on Azure for scalable analytics and enterprise data integration.
Built enterprise data ingestion and transformation pipelines across complex industrial system landscapes.
Developed graph-based representations of product structures and dependencies for analytical reasoning.
Designed and implemented an agentic AI framework for AI-supported decision workflows.
Built scalable analytical microservices and integrated reporting through modern BI technologies.
Coordinated backend, AI, and frontend development across the MYNR platform stack.

Sophia Wagner

AI Engineer & Technical Consultant

Last position:

AI Engineer & Technical Consultant at Freelance

Delivered ML pipelines for OCR, semantic search, and computer vision
Integrated Azure AI Agents and GPT workflows for automation and QA
Deployed cloud-based FastAPI services with scalable architecture
Created integration docs and advised on LLM production readiness

Rainer Langbehn

Senior IT Consultant, Senior Software Architect, Senior Software Developer, Senior DevOps Engineer

Last position:

Senior IT Consultant, Senior Software Architect, Senior Software Developer, Senior DevOps Engineer at Techniker Krankenkasse

Automation of the database major / minor releases for the TKeasy project
Concept for database major / minor release automation
As-is analysis
Evaluation of Redgate Flyway functionality
Concept creation
Products: Redgate Flyway, GitHub, Quest, Erwin Data Modeller, Oracle, Atlassian Jira, Atlassian Confluence
Skills: Docker, Continuous Delivery, Continuous Integration, Redgate Flyway, Major Releases, Minor Releases

Stefan Marx

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.

Stanislaus Stelle

Security Consultant at Rohde & Schwarz AG

Monheim am Rhein

Last position:

Security Consultant at Rohde & Schwarz AG at Star Labs GmbH

Worked on FPGA enhanced network encryption device with secure boot, TPM2.0 and smart card integration for BSI approved usage with Post Quantum Cryptography
Developed and audited Linux drivers
Collaborated using GitLab, Gerrit, Confluence and Jira
Technologies: C, C++, Secure Boot

Alexander Rautzenberg

IT Consultant

Monheim am Rhein

Last position:

Business Analyst at Financial Services Provider Landesbank

The Helaba ATLAS project aims to modernize core systems and make them future-proof. As part of the subproject, the existing legacy system for international payments is being replaced by a modern web-based application.

Analysis of functional and technical requirements
Analysis and optimization of business processes
Process modeling
Preparation and facilitation of workshops
Defining project scope and prioritizing requirements
Business process management (analysis, modeling, and optimization)
Specification of user stories
Designing business and authorization concepts
Testing and acceptance
Designing mockups in Figma
Creating the UI/UX style guide for web applications Approach: Scrum (agile) Technologies: Jira, Confluence, MS Teams, Conceptboard, Java, Vaadin, Figma

Markus Glagla

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 Hunkirchen

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 Hagemeyer-Lee

#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

Ayhan Gezer

Senior QA Engineer / Test Automation Engineer / SDET

Last position:

Senior QA Engineer / Test Automation Engineer / SDET at Rewe digital

Consulting, designing, and implementing the software testing lifecycle for multiple Android apps and backends Introducing test automation with Appium, SpringBootTest, RestAssured Setting up and managing emulators Developing an E2E library, an integration library, a Testcontainers library, and other libraries Developing, implementing, and advising on CI strategies Building the test environment with Testcontainers and virtualization Developing and implementing test cases for integration tests and end-to-end tests Establishing a maintainable test architecture with low entry barriers to simplify the creation of automated tests Some tools and technologies used: JUnit, RestAssured, Testcontainers, Kubedock, Appium, Android emulator, Jira Xray, Mockito, WireMock, Spring Framework, Kotlin

Manuel Schneider

Apro-IT – Make IT A Project!

Köln

Last position:

Project Manager at Univention

Industry: digital sovereignty, public sector

Content:

Project steering (teams: consulting, development, testing, deployment/operations)

Products and standards:

Jira, Confluence, Asana, Miro, Mural
Open Source, Keycloak, Open Xchange, ownCloud

Predrag Perovic