SSH Experts in Germany

• Restructuring of the network architecture/topology, followed by installation, setup and testing of the network at a small business.
• Resolution of server (permissions and roles) and connection problems (WAN, (V)LAN, WLAN).
• Infrastructure support and maintenance.
• Creation of documents such as manuals, architecture documents and design documents.
• Revision of manuals and technical documents, as well as creation of VBA macros.
• Use of AI and basic prompting, as well as formulation of AI requests.
• Adjustment of workflows due to legal requirements and optimization of existing workflows.
• Delivery of courses and training for adaptations, new features and changed workflows.
• Modeling basis: BPMN.
• System environment: MS Office 2019/365, Win10/11, Teams, Netgear (Switch), QNAP, Synology (NAS), Linux (Ubuntu).

• Modernization of a large-scale Java enterprise application*

The project is modernizing a complex enterprise application that has grown over many years. The existing Spring-based legacy system runs on Java 8, OSGi, and Eclipse RCP and is being gradually migrated to a modern, maintainable architecture with Java 25 and Quarkus.

Marcus works on analysis, architecture, refactoring, and implementation. One focus is on untangling historically grown structures and dependencies and on building a clean, sustainable Java and Quarkus technology stack.

Tools & technologies: Java 8, Java 25, Quarkus, Hibernate ORM with Panache, EclipseLink, OSGi, Eclipse RCP, Maven, JUnit, Mockito, REST, JSON, Git, Eclipse IDE, IntelliJ IDEA Ultimate, Jira, Confluence

• Error analysis and fixes including performance optimization of the in-house developed platform API
• Change and incident management in day-to-day operations
• Responsible for compliance with security and compliance requirements
• Vendor management for software development and maintenance
• Planning and execution of migration of legacy services to a cloud native platform

Role in the project: project staff, implementation team

Used skills: requirements analysis, IT service and application management, IT operations, error analysis and performance optimization, software maintenance and lifecycle management

Project environment: Cloud Native Platform (Kubernetes, Crossplane, AWS, ArgoCD, Grafana)

• ▶ Built real-time voice assistant (STT → LLM → TTS pipeline) benchmarking and evaluating multiple STT providers including faster-whisper and Azure Speech. achieved sub-3s latency, Groq API (Llama 3) with multi-turn memory - directly handling edge cases in dictation, names and passcode recognition.

• Delivered MVP-focused full-stack architecture for a health-sector client: Vite/React frontend, backend services on Google Cloud Run, and Supabase for database plus IAM/authentication.
• Supported product requirements engineering and prioritized cost-aware workload placement, implementing browser-side/edge computation where feasible before moving logic to backend services.

• Design and build of a fully isolated AWS offline environment with no outbound internet access for running a browser-based business application
• Design and implementation of a proxy and response service that terminates all external application calls inside the VPC and serves them from locally stored content; identification of the actual communication needs through measurement-based DNS query logging
• Creation of architecture designs and decision papers including a comparison of options (Application Load Balancer with Lambda and S3, reverse proxy on EC2, private API Gateway) assessed by operational effort, cost, and availability
• Transfer of the solution and operations documentation previously available only for Azure to an AWS target architecture, including reassignment of all services and operational processes
• Automated rollout as Infrastructure as Code (Terraform, CloudFormation) with CI deployment via GitHub Actions, plus setup of private DNS zones and an internal certificate chain for operation without internet access
• Creation of architecture, deployment, and operations documentation and handover to the customer
• Build-up of a private cloud platform on OpenStack at provider TelemaxX with Terraform, including FortiGate HA clusters, FortiManager, and Kubernetes
• Introduction of Policy as Code (Open Policy Agent, Conftest) as well as development of MCP servers (Model Context Protocol) to connect AI assistants to operations and project tools

Successes:

• Made the business application fully operable without internet access for the first time; the cause of the loading error was narrowed down systematically to missing CORS headers after the likely certificate issue was ruled out
• Fully transferred an existing Azure concept to AWS and replaced the manually created environment with a reproducible, CI-based rollout

Technology stack: AWS (VPC, Application Load Balancer, Lambda, S3, Route 53 private hosted zones and Resolver query logging, IAM, CloudWatch, EC2, CloudFormation), Infrastructure as Code (Terraform, CloudFormation, Remote State), CI/CD (GitHub Actions with OIDC, Azure DevOps Pipelines), OpenStack, FortiGate, FortiManager, Kubernetes, Policy as Code (Open Policy Agent, Conftest), offline and air-gap architectures, PKI & certificates (internal CA, TLS, CRL/OCSP), DNS, network segmentation, Linux, Windows Server, Python, Bash, PowerShell, YAML, JSON, architecture design & decision papers, documentation (Confluence, Markdown), Generative & Agentic AI (Model Context Protocol, Agentic AI Coding Tools)

• Founded an AI-powered scheduling and business-management SaaS for SMBs, owning technology strategy, architecture, product development, UX, billing and go-to-market execution.
• Architected and shipped a multi-tenant platform with REST APIs, RBAC, CRM, billing and notifications, powering the manager dashboard, admin console, booking experience and iOS/Android applications.
• Led and mentored 7 software engineers, 1 DevOps engineer, 1 QA engineer and 1 UX/UI designer, while remaining hands-on across backend, frontend and product delivery.
• Built AI voice and chat agents using Python/FastAPI, OpenAI and Anthropic APIs, RAG, pgvector and tool calling; integrated Twilio, Google Calendar/Meet, Stripe and Firebase.
• Owned production infrastructure and automated delivery across separate environments using Docker, Nginx, GitHub Actions and Grafana; represented the company at accelerators and international startup events.

Selected stack: Python, FastAPI, Node.js, Vue 3, React/Next.js, React Native, PostgreSQL, Redis, Docker

• Build and operate an end-to-end MLOps platform on Azure ML and Kubernetes (Kubeflow) for the automated deployment, monitoring, and scaling of forecasting models (including Temporal Fusion Transformer, Informer, Autoformer).
• Implement CI/CD pipelines in Azure DevOps for the full ML lifecycle – from resource provisioning (Terraform), data transformation (Hugging Face Datasets, Pandas, PyTorch, CUDA cluster) through training and evaluation to model registry and endpoint deployment.
• Integrate MLflow for experiment tracking, model versioning, performance monitoring, and automated registration in the Azure Model Registry.
• Develop and containerize PyTorch training jobs (Azure Notebook, Jupyter Notebooks) for price and time series forecasting (PFC models) with automatic rollout via Azure ML Endpoints and REST/gRPC interfaces, Docker containerization, secured with OAuth 2.0.
• Set up monitoring and alerting mechanisms (Prometheus, MLflow Metrics), log centralization, and cost monitoring.
• Automate infrastructure provisioning and model deployment using Terraform, Helm, and Azure CLI; connect to existing market data systems and event pipelines.
• Migrate existing workloads and databases (IONOS → Azure, MongoDB) with integration into central MLOps workflows and internal networks.
• Extend the platform with LLM-based tools (LangChain, LangServe) to integrate GPT-based analysis modules into existing Spring Boot services for market anomaly detection and automated reports.
• Analyze and architect a software solution to process large volumes of data efficiently (>3000 messages/sec.) (market data store).
• Spring Boot / Java 21 container development with RabbitMQ for distributing stock market data via MongoDB (Kubernetes) with fast storage of data in Redis RMaps, deduplication, forwarding messages to Read Model queues, and building Read Models for UI display in MongoDB.
• Integration of RESTHeart to create a REST API for MongoDB.
• Build an Angular frontend to simplify data queries and master data maintenance.
• Agentic coding with remote and local LLMs (Claude Sonnet, Ollama Qwen) and MCP servers.
• Develop Python scripts for transforming and cleaning incoming stock market data (Pandas, scikit-learn).

Task: Test tool development for Smart-Home IoT-based heating control Test tool development for Smart-Home HVAC heating and ventilation. Eliminating memory leaks in C/C++ within the CAN Analyzer application. Reviewing Python and Tcl/Tk code. Reviewing C-based simulator code for BOSCH Home Comfort cascade heating control using Visual Studio Code and Conan/Conda. Reviewing Delphi application: conversion to 64-bit. Reviewing PyQt6 user interface. SiL testing of domestic water heater control for memory leaks. Stability testing and continuous operation. Migration to Windows 11 24H2. Developing device connectivity with WinSock2 (WSAAPI, recv, send, select) for EMS/CAN IoT communication with C. Testing with virtual machines and Server Manager. Writing reports about the test cases. Logging with the RoboTT framework. Creating test procedure documentation with Docupedia. Bare-metal programming of embedded STM32 Cortex-M and simulation with Renode.io. In-depth familiarization with the SEGGER EmbOS firmware framework and its related system calls. Reviewing MATLAB/Sinumerik .m program files. Implementing redesigned OS schedulers in SEGGER EmbOS.Technologies: Embarcadero RAD Studio 10.2, Visual Studio Code, Sourcetree, Conan, Cmake, Conda, EmbOS, PyQt6, Qt6, Delphi VCL 32-bit, CAN, EMS, Powershell, MingW64, STM32 ARM-Cortex-M4F Renode.io, Windows Server 2022 Standard, RoboTT, IoT

Carve-out project: Creation of certification strategy, implementation and requirements plans across several standards — ISO/IEC 27001, ISO 9001, ISO 14001, ISO 22301, ISO/IEC 20000-1, BSI IT-Grundschutz and BSI TR- RESISCAN

• Cross-standard assessment of the current state and risk evaluation
• Coordination with stakeholders across departments: ISB, management, certification bodies, legal and data protection
• Consulting in the areas of information security, GRC and IT auditing

Internal systems with regulatory and security requirements could not be used directly by AI tools for incident triage, troubleshooting, and documentation search. The goal was to securely integrate these systems through MCP while preserving existing acce...

• Expansion and support of the product portfolio for video analytics and Computer Vision
• Requirements gathering and requirements engineering
• Consulting, project management, and coordination of pilots and the international rollout
• Tools: IP-based camera and video systems, Citrix Administration, OneNote, Microsoft Teams, Node-Red, Office 365, Age Verification, Qognify Umbrella, Thingsboard, Xovis 3D Sensors, AXIS Cameras, GK POS software, Atlassian JIRA

• Requirements analysis and replacement of local SharePoint as CMDB with open source NetBox to prepare for deploying Cisco ACI (SD-WAN) with Microsoft Azure
• Coordination with systems like Checkmk and Grasp
• Introduction and coordination of cmdbsyncer as CMDB data hub; further development of the syncer with Kuhn & Ruess GmbH
• Implementation of SNMPv3 on AIX LPAR/VIO, Linux, Windows, SAN/storage, network components (Cisco switches, F5 load balancers, Palo Alto and CheckPoint firewalls, iLO boards)
• Deployment and further development of the network scanner JDisc in cooperation with the vendor (Utimaco HSMs, Linux detection)
• Integration of NetBox, JDisc, and cmdbsyncer into the infrastructure using Docker containers
• End-user training: preparation, creation of materials, and delivery
• Creation of data flow and network diagrams
• Population and planning of IPv4/IPv6 with NetBox including VLAN import
• Dual-stack setup of servers and clients with IPv4 and IPv6
• Connection of REST interfaces for Checkmk, JDisc, vSphere, HMC, i-doit, NetBox Software: Confluence, Jira, MS Office 365, Teams, i-doit, NetBox, JDisc, cmdbsyncer, DB Visualizer, vSphere, HMC

• The goal of the project is to build a Greenfield FailSafe data center (FSRZ) as an emergency measure in accordance with BSI 200/4 against a cyberattack.
• Recovery of a project that had been running for several years. Re-initialization of the project: adjustment of the project organization, initiation of regular meetings, establishment of project controlling and project reporting, introduction of project risk management and consolidation of project documentation. Establishment of project governance and introduction of decision-making structures based on decision papers. Definition of deliverables and derivation of phase plans and the project plan. Personnel and resource planning. Coordination with “neighboring projects”, initiation of concept development and implementation. Management of the project with 8 subprojects and PMO. Budget planning and controlling (14,8 Mio). Support and coaching of the subprojects in their methodological approach. Coordination with suppliers and support of EU tenders. Coordination and processing of change requests. Coordination with line management regarding the economically viable operation of the FSRZ. Technical support for IT architecture in the areas of zOS, Windows and Linux, networking and IT security, for designing interim operations and extended regular operations for the FSRZ, planning emergency processes and emergency communication internally and externally.