VPN Experts in Dortmund

• 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.

• Technical design, prioritization, and hands-on implementation of AI automation, conversational AI, voice AI, and private AI solutions.
• Translation of business requirements into system architecture, conversation/workflow logic, APIs, data flows, and production-ready AI workflows.
• Development of backend and integration components with Python/FastAPI, PostgreSQL/pgvector, Redis, REST APIs, webhooks, and background jobs.
• Design and implementation of RAG architectures with local/private LLMs, embeddings, document processing, semantic search, and controlled access to company knowledge.
• Prompt engineering for LLM and voice/conversational AI applications; iterative optimization based on real processes, system responses, and quality requirements.
• Practical work with ElevenLabs and its APIs in a voice AI project, as well as technical evaluation and integration of voice AI components.
• Deployment and operation of Docker-based systems on Linux with Nginx, CI/CD, monitoring/logging, backup/restore, and reproducible deployment processes.

Development and evolutionary further development of a highly available, cloud-native microservice and integration architecture for dealer and retail processes in the Porsche Car Configurator.

Responsibilities

• Development of Java-/Kotlin-based backend, API, and integration components (Spring Boot)
• Integration of internal and external systems via REST/OpenAPI, GraphQL, Apache Kafka, and AWS SQS (synchronous and asynchronous)
• Implementation of stable, high-performance communication and data flows in a cloud-native platform architecture
• Processing of structured data formats (JSON, Protobuf, GraphQL schemas) based on existing API patterns
• Performance optimization of distributed microservices with reduced response times and higher operational stability
• Technical tests (unit, integration, and API tests) as well as error analysis in production-like environments
• AWS Infrastructure as Code with Terraform and AWS CDK
• CI/CD automation (build, test, and deployment pipelines) with GitHub Actions
• AI-supported feature implementation (GitHub Copilot Agent)

Label: Kotlin, Java 25, Spring Boot 4, Protobuf, TypeScript, AWS, Terraform, CDK, Apache Kafka, AWS SQS, REST/OpenAPI, GraphQL, JSON, PostgreSQL, Docker, GitHub Actions, Maven, Gradle, JUnit, Mockito, Testcontainers

• Optimization of the transmission media of the data links in the Ruhr area
• Configuration/expansion of switches and routers for an autonomous system AS
• Improve the network protocols used Layer 2/3 (OSI model), RSTP, broadcast, etc.
• Laying cables, crimping, antennas, routers, switches
• Maintenance, expansion, selection and prioritization of troubleshooting measures for network monitoring (PRTG, The Dude)
• Organization and new connection of another BGP peering, data center, NGN fiber optic
• VPN IPSec site connections for 6 sites with PFSense, Fritzbox
• Configuration of WLAN devices (Mikrotik, UBNT

Label: TCP/IP, VLAN, BGP, OSPF, MPLS, VPLS, routing protocols, WLAN, EoIP, PPPoE, routing, SNMP, DHCP, DNS, NAT, native IP, VLAN, Ethernet, VoIP., switches and routers from: Nortel, Cisco, MikroTik, UBNT., network management systems: The Dude, PRTG, UISP

• 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.