REST API Experts in Cologne

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

• Planning and implementation of a migration strategy for master and transaction data for the continuous loading of a cloud-independent database
• Creation and pilot implementation of a company-wide Business Data Model for customers, suppliers, contracts, products, prices, consumption, invoices, and dunning
• Concept and consulting for a Data Governance Framework incl. definition of committees, roles, processes, and metadata model
• Operationalization of the Data Governance Framework with definition of data standards
• Sub-project management in two pilot projects (PoCs) for Data Governance systems (ErwinDIS and Atlan)
• Training and coaching the data team in migration, data quality, and data modeling

• 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.

• 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

• Developed a real-time video analytics proof-of-concept for deployment on NVIDIA Jetson edge devices.
• Implemented DeepStream pipelines including object detection, tracking, human pose estimation, face anonymization, and zone intrusion detection.
• Built a Qt/Python demonstration UI interfacing with the AI pipeline via REST APIs.

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

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

• Perform secure code reviews and provide secure-coding guidance across the application and platform architecture.
• Engineer infrastructure security and design security-monitoring architecture, incident-response playbooks and Security-by-Design controls.

• Structured analysis and evaluation of business processes

• Gathering, documenting, and prioritizing requirements

• Creating business-friendly and technically executable process models

• Use of Camunda tools

• Deriving requirements and interfaces from BPMN diagrams

• Coordination with stakeholders and business units

• Translating business requirements into technical solution designs

• Implementing efficient and tailored applications

• Systematic collection, analysis, and documentation of requirements

• Prioritizing and validating requirements in close collaboration with stakeholders

• Alignment between business and development to ensure shared objectives

• Creating use cases, user stories, and acceptance criteria

• Continuous requirements and change management throughout the project lifecycle

• Define project goals and create project plans

• Delegate tasks and monitor project progress

• Monitor budgets and inform stakeholders

• Mendix: Architecture, development, and maintenance of custom applications (Microflows, Domain Model, Security, XPath)

• Modeling Mendix workflows for process optimization

• Develop scalable apps with Mendix including REST/SOAP integration with SAP, SQL, Azure & SharePoint

• UI design for Mendix using Atlas UI, Fluent UI, HTML, CSS, JavaScript

• Develop web & mobile apps with Mendix using agile methods (Scrum, Kanban)

• Implement business logic with Mendix Microflows and Nanoflows

• Performance optimization and architecture improvements for Mendix applications

• Conduct Mendix training

• Create technical documentation and best practices for Mendix

• Coaching and mentoring for low-code development with Mendix

• 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

• 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.

• 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

• Tested integration of TIBCO EBX with SAP S/4HANA via TIBCO BusinessWorks – proof of concept
• Implemented use case: communication between TIBCO EBX and SAP S/4HANA via IDocs to exchange material master data and business partner data
• Customized, configured, and implemented inbound and outbound processing in the SAP S/4HANA environment for communication with the TIBCO EBX software interface
• Distributed classes, characteristics, and values between TIBCO BusinessWorks and SAP S/4HANA and customized the inbound processing
• Documented the technical components

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