Meet our amazing team
Executive Management
Andrew Nisbet
With over 20 years of comprehensive accounting and finance experience, Andrew Nisbet joined Conterra as Vice President – Controller in November 2023. He has held a variety of roles throughout his career, showcasing a deep expertise in financial reporting, budgeting, and compliance. Known for his strategic vision and strong leadership skills, Andrew has a proven ability to enhance financial processes and drive organizational growth. Outside of work, Andrew enjoys spending time with his family, coaching youth soccer and hiking.
Kerry Grueneich
Kerry has over two decades of industry experience that have provided her a wealth of knowledge that she leverages to lead Conterra’s Revenue Enablement initiatives. She joined the Conterra team in 2024 and her experience leading enablement teams plays a critical role in the success of Conterra’s Sales organization, our Go-To-Market strategy and the overall customer experience.
Prior to joining Conterra, Kerry held a Senior leadership position at Segra where she led Sales Engineering, Sales Support and Sales Training teams. In addition, she has held Sales Engineering and Sales roles at Segra, AT&T and Windstream.
Kerry is an active member in the Women in Tech subcommittee of NC Tech and the Fiber Broadband Association’s Women in Fiber Committee and was recently recognized in their Women in Fiber Spotlight for her accomplishments in the industry.
In 2023, Kerry received the Cynopsis Top Women in Media Rising Star award for her achievements as a female leader in the technology/telecommunications industry.
Kerry is a mother of two girls and enjoys traveling, hiking and camping with her family.
Grant Sullivan
Grant Sullivan is an experienced telecom professional with over 20 years in the industry, currently leading Product Development and Marketing at Conterra. His career has spanned key leadership roles in product development, sales engineering, and service delivery, with a focus on driving innovation and delivering high-performance solutions.
Before joining Conterra, Grant served as Sr. Director of Service Delivery at Segra, where he oversaw teams responsible for complex installations and service implementations across multiple sales channels. Prior to that, he led Segra’s Sales Engineering division, growing the team significantly and spearheading major projects in networking and cloud services. His extensive experience also includes product and sales engineering roles at Windstream and NuVox, where he managed product development and engineered solutions to meet customer needs.
Todd DeWitt
Todd DeWitt began his journey in Telecom industry in 1996 with Oxford Networks in Lewiston, ME, where he spent two decades in Network and OSP Engineering. During that tenure, he helped develop a rural ILEC into a Facilities-based CLEC building Fiber-to-the-premise networks across Maine and transport systems into Boston.
In 2017, FirstLight Fiber acquired Oxford Networks. DeWitt transitioned to lead the IP Engineering /Operations teams to unify the initial Network asset purchases and create a strategy to scale. During his tenure at FirstLight, he played a pivotal role in the successful integration of multiple networks and people as part of the company’s aggressive acquisition strategy.
Todd joined Conterra Networks in the fall of 2021 to continue his passion in developing people and networks. He moved his family from Maine to North Carolina and now calls Charlotte home.
Craig Gunderson
Craig Gunderson has over 30 years of telecom experience in sales, operations, and executive leadership at corporate and field levels.
For the past 14 years, he served as Chief Operating Officer, President and (for the last 10 years) President & CEO of Oxford Networks until its sale to FirstLight. Oxford was a private equity backed, fiber optics based company that offered a diverse suite of transport, data and voice products and services to customers in the New England region. Under Craig’s leadership, Oxford achieved solid double-digit average annual growth rates by transforming the company from a traditional Local Exchange Carrier (Telephone Company) to a highly successful, fiber-based telecom services carrier.
Prior to his executive role at Oxford Networks, Craig spent eight years at Frontier Communications/Global Crossing, headquartered in Rochester, NY. At Frontier, he held various operations, sales, and marketing positions until he was promoted to General Manager of a newly formed business unit in Georgia resulting from acquisitions of two local telephone companies. After four years of sales and customer growth, Craig was promoted to Vice President and General Manager to run a larger region headquartered in Minnesota.
Before starting his impressive 30 plus year business career, Craig served for five years in the United States Army as an aviation and operations officer, achieving the rank of Captain in the Medical Service Corps. He received his undergraduate degree in Economics from Dickinson College in Carlisle, PA and his MBA from Georgia Southern University.
Mike Tompkins
Mike has over 27 years of experience in the telecommunications industry, leading operations, engineering, construction, IT, sales, and marketing teams at the executive leadership level. He is responsible for all activities related to service delivery, network and OSP engineering and operations, field operations, NOC and IT.
Mike joined Conterra in 2017 as Senior Vice President of Technical Services after working at Oxford Networks for nearly two decades. At Oxford Networks, he primarily held the position of Executive Vice President of Operations where he had overall responsibility for network operations, construction, engineering, customer service, managed service operations, data center operations, facilities, and safety. Mike also held the position of Senior Vice President of Operations at FirstLight Fiber after their acquisition of Oxford Networks in 2017.
Mike served 4 years in the United States Air Force, which included duty stations in Germany, Nevada and Saudi Arabia in support of Desert Shield and Desert Storm
Steve Keaveney
Mr. Keaveney is a career CFO in high-growth / rapidly changing organizations backed by Private Equity. Career highlights include:
- Connectivity Wireless – CFO (cellular infrastructure) – $80MM Sale to Private Equity Firm.
- Dulany Industries – CFO (Chemical Manufacturing) – Fractional CFO coordinated refinancing for large acquisition and cost accounting/pricing exercise for chemical manufacturing business.
- Innotrac – CFO (eCommerce Fulfillment) – $114MM LBO by PE Group taking NASDAQ company private.
- Beavex – CFO (Transportation) – $70MM Sale to PE Group, business doubled by acquisitions.
- Etel Group – SVP Finance (Telecom) – PE-Backed – Startup to $130MM Trade Sale to Telecom Austria.
- Cable Management – CFO (Telecom) – PE-Backed Startup to $100M Trade sale to UPC Europe.
- Transportation Insurance Experts President/CFO (Insurance) – Restructured insurance company with $50MM annual premium.
He resides in Atlanta and holds an MBA in Finance from Pepperdine University, a BA in Accounting from Villanova University, and a Certified Public Accountant (CPA). Keaveney started his career as an auditor with Deloitte in NYC.
Michael Brady
Michael Brady has over 20 years of sales, general management and leadership experience providing broadband infrastructure services across many of the markets Conterra serves. He is responsible for leading Conterra Networks’ sales, marketing, and product management organizations throughout its operating footprint across the United States.
Michael held numerous senior leadership roles at Lumen Technologies (formerly CenturyLink) and Level 3 Communications (acquired by Lumen Technologies) where he was responsible for sales, sales engineering, field marketing and customer success across the wholesale and enterprise vertical segments. Immediately prior to joining Conterra, Michael served as CenturyLink’s VP East Region where he was responsible for Enterprise sales across 35 states.
Michael earned his M.S. degree in economics from the University of North Carolina at Charlotte and Executive Education Certification from the University of Denver. Michael currently is a member of the board of advisors for Adtech Corp and Cuemby.
Christopher Harris
Christopher Harris is Chief Technology and Security Officer. In this role, he leads Data & Voice Network Architecture, Cyber Security, IT Systems & DevOps Strategic Planning and assists with Market Planning, Product Development & Lifecycle Management. Chris has 20 years of Telecommunication experience, of which, 17 years is with Conterra.
Chris’ areas of expertise include wireless, fiber and network logical design, cyber security, information systems, business and market strategy and development, construction, and operations.
Chris has a BSEE from the University of Idaho and is a registered Professional Engineer in State of North Carolina.
André Hall
André Hall is a seasoned corporate attorney with thirty years’ experience representing multinational corporations in complex transactions, regulatory compliance, and dispute resolution matters. André is a former public company general counsel and chief legal officer of $2 billion multinational NYSE-listed company where he led various legal and compliance teams responsible for all legal matters encountered by the company. His overall experience is broad and touches most areas encountered in complex domestic and international business transactions. André has represented companies in the consumer goods, chemicals, aerospace and defense, energy, and construction and engineering industries. His primary focus has been on complex commercial transactions, regulatory compliance, mergers and acquisitions, and the strategic management of complex litigation and dispute resolution.
André is a graduate of Furman University and the University of North Carolina at Chapel Hill School of Law.
Tim Leighton
Tim Leighton has more than 24 years of telecom experience and has held management positions in start-up, privately held and large publicly traded companies. His experience includes revenue accounting, commissions accounting, FP&A, mergers and acquisition, billing process and data warehousing.
Tim began his career in telecom at MCI Communications. He then joined US LEC where he was Sr. Director of Revenue Accounting before merging with Paetec and becoming VP of FP&A. He was integral to the acquisition and integration of McLeodUSA and Cavalier Telephone, elevating Paetec to $2B in revenues before being acquired by Windstream. Joining Conterra in 2014, Tim has helped integrate four acquired companies, developing the tools and processes to facilitate management reporting, capex tracking, commissions administration, contract management, billing audit and KPI metrics along with managing budgeting and forecasting processes and M&A analysis.
Gigi Sizer
Gigi Sizer has over 30 years’ experience in accounting and financial management, specializing in systems integrations, month-end closing procedures, financial statement preparation, cash and treasury management functions and staff management.
She began her telecom career as Conterra’s Director-Accounting and Reporting from 2013-2018 where she managed the daily operations of the company’s accounting and tax activities. Currently, Gigi’s responsibilities include oversight and implementation of the ERP and other financial systems as well as evaluating and creating business processes and procedures and coordinating other systems and financial projects.
Prior to joining Conterra, Gigi served as Chief Financial Officer and Assistant Treasurer for the National Trust Community Investment Corporation, a Washington, DC tax credit syndicator, managing real estate investment funds totaling $500 million. Before her tenure at the National Trust, Gigi held the position of Director of Operations for Davita, Inc., a publicly traded, $10 billion healthcare provider, where she provided financial and operating analytics to senior management and was responsible for a division’s $100M annual budget preparation and analysis. She has also held the position of Controller at several other small and medium-sized companies.
Gigi is a Certified Public Accountant with a B.S. in Business Administration, Accounting concentration from Winthrop University in Rock Hill, SC.
Adrian Garcia
Adrian Garcia has over 18 years of telecommunications and technical sales experience. He has held a wide variety of roles in management, sales, operations, and sales engineering. His expertise includes technical solution engineering, talent development, and management while producing high-profitable growth for telecom companies. Previously to his current role, Adrian was the Conterra Area Sales Manager for the Southwest Market where he was responsible for developing and driving enterprise sales, consistently surpassing objectives.
Prior to Conterra he was the West Texas and New Mexico market Sales Engineer for Level 3 Communications. He supported customers and networks in both metro and global scales. From 2008 to 2014, Adrian worked as a sales leader, technical consultant, and account executive at AT&T. He was the technical sales resource supporting over 20 account executives in El Paso, Houston, and South Texas Markets. In these various roles, he contributed successfully and extensively to the company’s aggressive network fiber buildout initiatives.
Dawna Hannan
Dawna Hannan has been in the telecommunications industry for over 37 years. Dawna joined Conterra Networks in March 2018 where she is responsible for Human Resources and Telecom Regulatory.
Prior to joining Conterra Networks, Hannan was the Director of Human Resources & ILEC Regulatory Affairs for FirstLight in Lewiston, Maine. Prior to the FirstLight’s acquisition of Oxford Networks in 2017, Hannan was Vice President – Human Resources & Regulatory Affairs. Hannan joined Oxford Networks in 1994 after they acquired the GTE Maine properties.
Dawna held various managerial positions with GTE including managing GTE New York’s customer service order center in Johnstown, New York.
In her previous role in Maine, Hannan served as a Director and President of the Telephone Association of New England (TANE), Director & President of the Telephone Association of Maine (TAM), Chair of the State of Maine E-911 Advisory Council, Vice Chair – United Way of Androscoggin County Board and a member of the Central Maine Medical Center’s Associate’s Board. Hannan was inducted into the TANE Hall of Fame in 2015. Hannan attended Franklin Pierce College in Concord, NH.
Dawna lives in Mint Hill, NC, with her husband Mark.
Jim Dickens
Jim Dickens is the Vice President, OSP Engineering and Construction. In this role, Jim is creating company standards across multiple regions, which include several previous acquisitions. As the leader of the largest capital expenditure budget within Conterra, Jim is creating synergies that will drive improved cost efficiencies and operational effectiveness in the construction processes.
Prior to joining Conterra, Jim was the Vice President of Operations with CenturyLink/Lumen for the states of North Carolina, South Carolina, and Tennessee. As part of this role, Jim served on the North Carolina Chamber. Jim’s industry experience spans more than 30-years, with 20-years at senior leadership levels. He began his career with Sprint in Florida, where he held the titles of CO Manager, NOC Technical Manager and Network Sales Manager. Subsequent to Sprint, Jim was a Senior Director of Operations with Time Warner Telecom/tw telecom and Level 3. In his spare time, Jim is an avid Harley-Davidson enthusiast.
Tony Doria
Tony Doria leads the Service Delivery/PMO, Customer Care, Service Fulfillment, and Network Operations Center (NOC) teams. Tony has 24 years of leadership experience in the telecommunications industry including roles in information technology, operations management, and executive leadership.
Prior to joining Conterra Networks in 2010, he was the Information Technology Director for twelve years for an affiliated company, Centris Information Services. Before that, Mr. Doria spent thirteen years managing information services for an oil and gas company in Houston, Texas, Singapore, and Jakarta, Indonesia.
Tony has a BS Computer Science degree from the University of Houston.
John Marquis
John Marquis has over 30 years of experience in the telecommunications industry, leading field operations and network operations center (NOC). John has been with Conterra 11 years leading the field operations, network operations center, 811 fiber protection, service delivery and service fulfillment teams.
John worked 7 years previously with KMC telecom as the director of operations maintaining 17 CLEC markets throughout the country.
John served for 10 years in the United States Marine Corps.
Mark Gossett
Mark Gossett has over 15 years of finance and accounting experience in various management positions. Mark joined Conterra in 2018, leads the corporate accounting team, which includes the financial reporting, billing, accounts payable, regulatory reporting, and external financial compliance functions.
Prior to joining Conterra, Mark worked in the audit practice with the public accounting firm Grant Thornton where he served a wide array of public and privately held companies, with an emphasis on the telecommunications and technology industries.
He is an active Certified Public Accountant and graduated from Biola University with a Bachelor of Science in Business Administration with an emphasis in Accounting.
Larry Wilson
Larry Wilson is a telecommunications industry veteran with over 30 years of cross-functional telecommunications experience including roles in sales, operations, engineering, and marketing
For the last 18 years, Larry focused on selling telecommunications services to national and international carriers. For the most recent 10 years, he has specialized in lit and dark fiber infrastructure solutions for the wireless carrier industry including fiber to the tower, small cell, and DAS
His critical thinking and ability to adapt quickly to changing markets resulted in significant sales growth throughout his career. His expertise includes the development of long-term strategic relationships, global account strategy, building and managing strong senior level sales teams, and developing emerging markets at both start-up and industry-leading companies within the telecommunications industry
Previously, Larry held the position of Senior Vice President, Carrier Sales at FiberLight, LLC with responsibility for strategic direction and management of all sales related activities within the FiberLight wholesale carrier customer segment. He has held many leadership positions with companies such as PEG Bandwidth, MCI, New Edge Networks, Brooks Fiber, Level 3 and Covad
Larry served in the United States Air Force as a Non-Commissioned Officer within the Air Force Communications Command and received an honorable discharge.
Bob Ziemba
Bob Ziemba joined Network Communications, now Conterra Networks, in 2015 bringing 40 years of experience in the telecommunications industry. Bob leads network engineering and operations of both voice and data networks.
Before joining Network Communications, he had a similar technical leadership position for fifteen years for an affiliated company, NetworkIP.
Prior to joining the Network Family of Companies, Bob spent 12 years managing the technical operations in the western half of the US for Reuters America and 13 years at a small company named SPCommunication where he started as a technician and was promoted to several engineering and technical operations positions as the company evolved through several acquisitions to become known as Sprint.
Mike Padula
Mike has over 25 years in the telecommunication and cloud-based marketplace. Mike joined Conterra in 2021 and is a result driven, goal-oriented sales leader with a passion in building high performing sales teams.
Prior to joining Conterra, Mike held executive leadership positions for Level 3 Communications, Presidio, PGi, and Lumen where he was responsible for SMB, National, Global Enterprise, Wholesale, SLED & Partner Sales.
In his spare time, Mike enjoys making memories with his family in Atlanta, Georgia.
Beau Griffin
Beau Griffin is the National Vice President of Fiber Operations, overseeing the nationwide fiber optic network. He leads the design and discovery phases, manages costs, and ensures quality assurance throughout engineering, construction, and operations. Previously, he served as the Director of the South-Central Region Fiber Network at Conterra Networks, where he enhanced employee productivity and monitored revenue margins. Before that, Beau was a Project Manager at Network USA, LLC, where he coordinated telecom projects from site preparation to equipment installation. With nearly 20 years of experience in telecommunications and a degree from Northwestern State University, Beau’s expertise continues to drive innovation and success in the industry.
Business Leaders
Board Members
Jamie Crotin
James Scully
Alina Osorio
Greg Guerra
Michael Hurley
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