REST API Experts in Dortmund

Manufacturing intelligence platform with enterprise workflows, RAG, real-time AI assistant features, and multi-repository backend architecture.

• Built and extended production AI/backend services with Django, DRF, FastAPI, GraphQL, Celery, PostgreSQL, MySQL, Redis, and WebSockets across a modular multi-repository platform.
• Contributed to ARIS V2, a real-time manufacturing AI assistant using LangChain, LangGraph, MCP tool orchestration, planning/execution flows, OpenAI, AWS Bedrock, Qdrant, and Elasticsearch/OpenSearch-backed retrieval.
• Supported rollout expansion from ARIS V1 in 4 of 17 client production plants to ARIS V2 currently active in 13 of 17 plants, increasing real-world deployment coverage to more than 50% of the client footprint.
• Worked on document-grounded RAG functionality including ingestion, OCR, chunking, embeddings, indexing, retrieval, reranking, and grounded answer generation for industrial workflows.

Stack: Python, Django, DRF, FastAPI, LangChain, LangGraph, GraphQL, Celery, WebSockets, OpenAI, AWS Bedrock, Qdrant, Elasticsearch/OpenSearch, PostgreSQL, MySQL, Redis, Docker.

• Development of software and system support for RPG development.
• Development, optimization and maintenance of programs in RPG (RPG II to ILE Free Format).
• Performing integration tasks, data management as well as applying and managing system updates.
• User support and training to ensure smooth system operation.

• New development of a web app to manage and configure counting devices for large events
• Technologies: .NET 10, C#, Blazor, MudBlazor, MySQL, Git

• Development of an automated job-scouting workflow for the aggregation and LLM-based evaluation of job postings from RSS feeds and APIs.
• Development of a Telegram bot for voice and text messages, featuring LLM-supported processing, summarization, and structured JSON output.
• Implementation of a personal task-planning assistant using n8n, OpenRouter, and Supabase for automated daily and knowledge organization.
• Development of LLM chatbots for structured knowledge retrieval utilizing prompt constraints, guardrails, and forced output formats.

• Requirement engineering for Ombudsstelle and creation of technical user stories for EPA V3
• Handling of objections and revocations via mail and letter with high transaction mail volume
• Coordination with other teams on interfaces
• Design of a highly available, high-throughput solution on OpenShift with Java backend microservices
• Implementation and extension of microservices
• Infrastructure setup for deployment on OpenShift/Kubernetes including Jenkins pipelines
• Integration with BitIAM, TI-M Fachdienst, Consent Keeper and FDV
• Capture of requirements from DevOps operations and business units
• Continuous integration and Scrum practices
• Use cases: Kassenfusion, Opt-Out, Last Test, Widerspruchsmanagement
• Integration test automation and feature extensions including Spring Boot 3 updates

Building an observability and alerting solution for Business Central Job Queue monitoring

• Built a central monitoring solution to track the Business Central Job Queue in a multi-organization environment in Azure DevOps
• Integrated Azure Application Insights and Log Analytics for structured collection and analysis of job runtimes and error events
• Developed KQL queries for targeted analysis of failed jobs and detection of error patterns
• Connected Grafana and Power BI to visualize operational metrics and job status in real time
• Implemented an automated alerting workflow with Power Automate – when a job fails, a notification email is sent immediately
• Ensured transparency about the state of productive background processes during live operations

Result: Full transparency over failed Business Central jobs · Clear reduction in response time through automated email alerting · Stable foundation for proactive operation of productive background processes

Technologies: Azure DevOps | Application Insights | Log Analytics | KQL | Grafana | Power Automate | Power BI | Business Central | Azure Monitor

• Initial assessment of requirements based on a business value prioritization framework
• Identification of issues as well as requirement gathering and evaluation using UML, BPMN, and design thinking methods for iterative requirements analysis through interviews and workshops
• Use of user story mapping in Miro to visualize and align functional requirements (e.g. correct transmission of all application data and attachments to the specialist system) as well as non-functional requirements (e.g. complete and verifiable deletion of an applicant's data) with stakeholders
• Proactive stakeholder management of internal and external stakeholders from public authorities, business units, organizations, and companies
• Preparation of status reports to communicate project progress and upcoming tasks transparently
• Responsibility for a REST-based integration solution (middleware) for secure data exchange between core systems and external specialist applications; ensuring stability and performance in day-to-day operations
• Support for Product Owners in prioritizing backlog items and in product discovery
• Communication of planning to internal and external stakeholders as well as interim assumption of Product Owner tasks and responsibilities during a staff change

• SD-WAN solution by Aruba – Swiss energy company (330 sites): design and implementation of an SD-WAN branch solution with Aruba 9004 gateways, encrypted overlay, policy-based routing, WAN load balancing, and centralized management via Aruba Central.
• LAN/WLAN & security – schools in Germany (9 sites): deployment of Aruba switches & AP-505, FortiGate 80F firewalls; setup of Checkmk monitoring, incident and change management, and secure admin access (BeyondTrust).
• Multi-site security – energy billing company (20 sites): deployment of a complete Fortinet solution (FortiGate HA cluster, FortiSwitch PoE, FortiAP), IPsec remote-access VPN via FortiClient, centralized management via FortiCloud, IntraID authentication, operations and incident management.
• Data center migration – German client: migration of data center switches (Mellanox), firewall cluster, and OfficeConnect switches to a new data center; securing configurations, implementing HA designs, testing, monitoring, and coordinated change and incident processes. Setup of two new 6300 M VSX clustered switches.
• Data center security – university hospital: implementation of a high-availability FortiGate 400F firewall cluster across three data centers; security policy design, operational support, and change/incident management.
• Enterprise campus & network access control – manufacturing company in Germany: introduction of Aruba ClearPass NAC, setup of a VSX-based switching architecture, secure WLAN access with MPSK, and integration into existing networks.
• EU client (Germany & Poland) – Sophos firewalls: operations, incident and change management of Sophos firewalls including IPsec VPN; troubleshooting and ongoing optimization of security configurations.
• Network modernization – pharmacy client in Germany: design and rollout of core and access switching (Mellanox, Aruba Instant On), migration from Sophos to Fortinet firewalls, network segmentation, and security hardening.

• Carve-out of Wärme+ customers from EWE to the new company WCG with around 24,000 metering points.
• Development of a migration approach, data migration, process redesign and migration.
• Management of service providers, reporting to the steering committee and executive management.
• Tools: Jira, SharePoint, Draw.io, SAP S/4, SAP PM, WILKEN (ENER:GY, P5), carve-out.

• Setting up and consulting a startup for organizational development (AI-supported)
• Vision and mission workshops
• Marketing roadmap and process design
• Development of sales processes (sales funnel, lead generation)
• Brand building and social media omnichannel strategies
• Content generation for audio, video, and posts (AI-supported)
• Agile consulting and SAFe implementation
• Atlassian consulting and setup of Confluence and Jira (workflows, dashboards, reporting)
• Setup of a podcast and video studio including live streaming setup
• Selection and implementation of hardware and software
• Website creation and brand building
• CMS implementation based on Typo3
• Consulting in sales, marketing, and social media
• Supporting companies in the efficient use of AI technologies
• Strategy development and consulting on implementing AI strategies
• Change management and supporting teams in AI adoption, including training
• Technical expertise in machine learning, data processing, and large language models (LLMs) like Llama, Claude, and OpenAI GPT
• Selection, fine-tuning, and integration of LLMs into business processes
• Consulting on ethics and governance for responsible AI use
• Conducting tailored training for executives and teams
• AI analysis of various large language models (Llama, OpenAI, Mistral)
• Creation and training of custom GPTs focused on organizational development (product vision, OKR, agile maturity)
• Development of a chatbot on agile maturity
• Development of an AI-generated survey to assess organizational agility
• Setup of local offline GPTs with a focus on data protection and GDPR compliance
• Conducting AI workshops for SMEs and mid-sized companies

• Designed and implemented the system architecture for scalable document workflows, improving stability and performance.
• Optimized the login flow with TOTP-based MFA, reducing complexity and login time by 35%.
• Built secure backend APIs for document upload, signing, and management.
• Developed encrypted file handling with AWS S3 pre-signed URLs, ensuring GDPR-compliant data protection.
• Implemented JWT-based role authentication, strengthening access control and overall platform security and reducing code and database complexity.
• Optimized database queries and caching using ORM, reducing API response time by 40%.
• Integrated real-time webhook updates, enhancing workflow transparency and user experience.

• Various small consultations, e.g. concepts and arcitectures.
• Updating my Matlab, Linux, IPv6, Cyber-Security, C++ (up to 23) and Python skills.

• Implementation of various interfaces for subsystems and connection to external devices (cameras, scanners, digital lockers)
• Development of various interfaces in the used cars area
• Realization of various prototypes
• Support in UI/UX and data analytics
• Development of frontend and backend solutions
• Kubernetes migration
• Building CI/CD pipelines
• Communication with the business unit and technical design of new solutions
• Cross-team alignment and coordination within the team
• Overview of the entire technology stack and related systems
• Documentation, preparation, and conducting of reviews
• Supporting the team and coordinating releases and key milestones