Tomáš GRYGIER

Lead Network Engineer

Ostrava, Czechia | +420 770 176 052 | [email protected] | LinkedIn

Experienced Network Engineer with over 15 years in enterprise WAN, LAN, and SD-WAN infrastructure. Certified in Cisco, Juniper, Versa, Silverpeak, and Riverbed technologies, with expertise in network troubleshooting, architecture design, automation (Python, Ansible), and operations in large-scale service provider environments. Proven success in driving complex network transitions, performance optimization, and critical infrastructure support.

Experience

Customer Lead Engineer

Verizon Enterprise August 2019 - Present

• Led NOC management takeover projects for several large global enterprises.
• Contributed to transitions of MPLS customers to Viptela/Cisco SD-WAN and to Silverpeak SD-WAN platforms.
• Managed a global Cisco SD-WAN network (vEdge, cEdge ISR-1100 and Catalyst 8200).
• Oversaw global wireless networks (Cisco, Aruba), WAN (MPLS, DMVPN, SD-WAN – Cisco, Silverpeak, Versa) and wired LAN (HPE/Aruba and Cisco Catalyst).
• Managed Zscaler (ZPA, ZIA) for a cloud-based customer.
• Achievements:
  • Deployed automation in 2019, reducing incident workload by hundreds per month.
  • Recognized by the customer’s CTO in 2020 for a critical role in ransomware mitigation.
  • Credited in 2021 for improving the Network Emergency Kit process, accelerating recovery during full site outages.
  • Developed custom automation in 2023 to meet unique SD-WAN notification requirements for a new customer.

Network Consultant

Freelancer
August 2024 – Present

• Design and implement network solutions for small business clients.
• Provide network designs and on-site implementation.
• Develop automation tools focused on API integration using Node.js, Python, and PHP.
• Deploy solutions based on Ubiquiti and MikroTik hardware.

Center of Excellence Engineer

Verizon Enterprise September 2018 – July 2019

• Provided 3rd line support for operations teams. Daily tasks included network management for large-scale global customers: incident resolution, change implementation, patching, and security management.
• Maintained Cisco WLAN infrastructure (55xx controllers) and led migration to Catalyst 9800.
• Led site transformations to Aruba Central for wired and wireless LAN.
• Created training materials and documentation for new network products and solutions.
• Translated business requirements into network solutions.
• Acted as a liaison between operations teams and business stakeholders.
• Achievements:
  • Maintained strong relationships, contributing to satisfaction scores above 8/10.

Senior Network Engineer

Verizon Enterprise September 2010 - August 2018

• Operated Verizon’s global IP backbone with Cisco ASR9k, ESR10k, GSR12k, and Juniper MX series.
• Collaborated with other ISPs to resolve major outages.
• Specialized in incident resolution, root cause analysis, multi-vendor collaboration, and vendor escalation handling.
• Achievements:
  • Accelerated DSL product onboarding in 2012, enabling faster service launches.
  • Identified a critical bug in Cisco C3800 in 2015, preventing degraded services and RMAs for hundreds of customers.
  • Contributed to Verizon’s first Cisco IWAN deployment in 2016.

Junior Network Engineer

Verizon Enterprise July 2009 - August 2010

• Provided Tier 1 support for public IP business customers.
• Monitored and managed xDSL, Ethernet, and SDH circuits, as well as customer premises equipment.
• Achievements:
  • Awarded “Best Engineer” in 2010.

Projects

Network Academy

Verizon Enterprise September 2014 - December 2020

• Co-founded an in-house networking academy to support certification training.
• Trained 40 engineers annually, with 100 % success rate at certification exams.
• Delivered preparation courses for Juniper and Cisco.
• Migrated physical training lab to a virtual environment (ESXi, EVE-NG) reducing operational cost and increasing training capacity.

Skills

• Networking: Cisco IOS, AirOS, Junos, Versa, Silverpeak, Riverbed
• Automation & Programming: Python, PHP, JavaScript, TypeScript, Ansible
• Tools & Platforms: Wireshark, Iperf, Git, React, EVE-NG
• Soft & Professional Skills: Troubleshooting, stakeholder communication, documentation, team collaboration, adaptability, self-motivation, solution orientation
• Driving License: Category B

Education

Master’s Degree in Telecommunication

VŠB - TU Ostrava 2007 - 2009

• Graduated with honors in Optoelectronics, Security, and Diagnostics
• Recognized by the rector for outstanding academic results

Bachelor’s Degree in Information Technology

VŠB - TU Ostrava 2004 - 2007

• Thesis: Diagnostics of Wireless Devices
• Recognized by the rector for academic excellence

Languages

• English: Fluent
• Czech: Native
• German: Basic
• Polish: Basic

Interests

• Hobbies: Enthusiastic long-distance trail runner, road cyclist, and explorer of network technology trends.