VPN Experts in Essen

Gronic Ident & Sign

Core technologies: Android, Jetpack Compose, Retrofit, Regula Document Reader, Adobe Sign

Android app on dedicated devices for identifications and electronic signatures at the PoS

• 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.

• CHG Meridian AG is a financial company focused on leasing in the areas of IT technology, logistics and medical technology and is regulated by BaFin. One part of the company is Return to Remarketing, where devices delivered to the technology center (notebooks, smartphones, tablets, etc.) are prepared for resale. The project I supported was responsible for enabling damage assessment of returned lease devices, documenting them visually in the form of pictures, enabling invoicing for the customer, and making the pictures available via the in-house customer platform. This was achieved through a combination of in-house development within the internal development department and the use of SaaS products. The second project was the transition of SaaS tendering software, purchased by the business unit, into the operations of the CHG IT department. Evaluation of security questions in relation to BaFin requirements, development of an authorization concept, implementation of single sign-on, documentation of the application in the CHG systems (CMDB, iKnow, etc.) and handover into operations.

Used technologies and methods: NIS2, DORA, agile software development, Scrum, Kanban, ServiceNow, SaaS, MS Teams, MS SharePoint, Active Directory, Entra ID, CMDB, incident management, change management, request management, service level agreement

• 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

• Provided expert level consulting for lifecycle, upgrades and refresh activities
• Used Remedy for effort recording and billing to customers
• Used ServiceNow for service management and workflow
• Used Jira for project management with agile/Scrum methods
• Used Confluence for documentation
• Worked with customer-specific software tools
• Worked with customer-provided and secured hardware suitable for IT security operations infrastructure setup for customers
• Built firewall rule sets and handed over to service owner and delivery teams
• Environment: Cisco ASA, Cisco Firepower, CSM, Cisco AnyConnect, Cisco ISE, Check Point VSX and gateways

• 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.