Executive Team


Shane Buckley

Chief Executive Officer

Shane Buckley is President and Chief Executive Officer, having previously held the title of President and Chief Operating Officer before his appointment as CEO in 2022. He brings more than 25 years of executive management experience to the team with prior roles including CEO at Xirrus, General Manager and Senior Vice President at NETGEAR, President and CEO of Rohati Systems, and COO at Nevis Networks. Shane is a graduate of engineering from the Munster Technological University in Ireland.  


Chaim Mazal

Chief Security Officer

Chaim Mazal is Chief Security Officer with responsibility for global security, information technology, network operations, governance, risk, compliance, internal business systems, as well as the security of Gigamon product offerings. Prior to joining Gigamon he held similar roles with several industry leaders, most recently at Kandi, where he was the SVP of Technology and CISO. Chaim is a lifetime member of the Open Web Application Security Project (OWASP) Foundation and currently sits on several advisory boards, including Cloudflare, Gitlab, and Lacework. Chaim holds a bachelor’s degree from the Rabbinical College of America.


Christel Ventura

Chief People Officer

Christel Ventura is Chief People Officer where she leads the team responsible for staffing world-class teams and nurturing corporate culture. Prior to joining Gigamon in 2015, Christel led Global HR Shared Services at Yahoo! and prior to that was an HR Business Partner at both Intuit and Credence Systems. Christel holds a BA in Sociology with Specialization in Business Administration from the University of California, Los Angeles.


Tony Jarjoura

Interim Chief Financial Officer

Tony Jarjoura, CPA, is the Interim Chief Financial Officer and leads the global finance team and accounting operations. He brings more than 20 years of financial, technical, and operational experience to the executive team. Prior to Gigamon, Tony served high-tech growth companies and gained valuable experience in the assurance practice of Ernst & Young LLP. Tony holds a BS in Business Administration, magna cum laude, from the University of San Francisco, California, and is a certified public accountant.


Guy Colpitts

General Counsel

Guy Colpitts is General Counsel, with a legal career spanning over two decades in the technology sector. Guy oversees all company legal affairs, from corporate governance and intellectual property management to complex business transactions and compliance matters. Prior to Gigamon, Guy served in progressively senior legal roles at various companies, including as General Counsel for DataDirect Networks and Tintri.


James Robb

Senior Vice President of Corporate Development

James Robb is Senior Vice President of Corporate Development with responsibility for mergers and acquisitions, including sourcing, valuation, integration planning, due diligence, and negotiations. James joins Gigamon from Accruent where he served in numerous executive roles including Vice President of Corporate Development and Chief Financial Officer. Over the course of his career, he has led more than 30 successful transactions totaling nearly $4 billion in enterprise value. James holds an MBA in Entrepreneurship from the Acton School of Business and a BS in Industrial Distribution from the Texas A&M University College of Engineering.


John Giacomini

Chief Revenue Officer

John Giacomini is Chief Revenue Officer with responsibility for revenue generating activities and leading the global sales, sales engineering, and channel organizations. Prior to joining Gigamon, he served as senior vice president of sales for Netskope, a leading cloud security company. With 25+ years of hands-on experience in tech sales, John has successfully driven revenue growth for companies like Agari Data, Cylance, Forcepoint, and Blue Coat. John actively invests in tech startups and holds a BA in public relations and journalism from Long Beach State University.


Karl Van den Bergh

Chief Marketing Officer

Karl Van den Bergh is Chief Marketing Officer and is responsible for global awareness and demand for the Gigamon solution portfolio. Throughout his 20+ plus year career, Karl has held go-to-market and product leadership roles in $1B+ tech companies as well as working as part of the executive team at early-stage startups. Prior to Gigamon, Karl was CMO at DataStax.  Karl holds a BA in Physics from Trinity College Dublin, a Master of Computer Science degree from Imperial College London and a Diploma in Humanities from Loppiano University in Florence Italy.


Ljubo Mandic

Senior Vice President, Special Projects

Ljubo Mandic brings more than 30 years of experience in software and hardware engineering to Gigamon. In prior roles, Ljubo was Vice President at Juniper Networks and Vice President of R&D at Harmonic Inc. Ljubo holds a Bachelor of Science degree in Computer Science and Engineering from the University of Sarajevo, a Master of Science in Computer Engineering degree from Santa Clara University and an MBA from Jones International University. He also has additional training from the Executive Program at Stanford University, and a Professional Coaching certification from UC Davis Continuing and Professional Education.


Michael Dickman

Chief Product and Development Officer

Michael Dickman is the Chief Product and Development Officer, overseeing product lifecycle from strategy to execution. He leads the product management, software and hardware engineering, alliances, and product marketing functions. Prior to Gigamon, he was Senior Vice President for product management and technical marketing at HPE Aruba Networking, where he accelerated cloud services across management, network optimization, and user experience. He previously innovated a mobile-first strategy for Aruba Switching in product management and later served as general manager. Earlier in his career, he held various leadership roles in enterprise networking at Cisco. Before joining Cisco, he began his career at the Boston Consulting Group. Michael holds an MBA from the Kellogg School of Management and BA degrees in Applied Math-Economics and History from Brown University.


Sandhya Sagar

Chief of Staff

Sandhya Sagar is the Chief of Staff, with responsibility for helping the organization deliver on strategic initiatives, improve operational performance, and develop the mission critical capabilities needed to exceed our business objectives. She has more than 20 years of experience and has held positions of increasing responsibility and complexity, most recently as Vice President of Product Operations for Gigamon. Prior to joining Gigamon, Sandhya held engineering and management roles at Juniper Networks, Tellabs, and Nortel Networks. Sandhya holds a BS degree in Material Science and Technology from the National Institute of Technology Karnataka and an MS in Material Science and Engineering from the University of Cincinnati.


Tim Watson

Senior Vice President of Operations

Tim Watson is Senior Vice President with responsibility for go-to-market, supply chain, and manufacturing operations, providing operational oversight through the full customer lifecycle. He brings more than 15 years of experience in building teams focused on enhancing the ease of doing business. Prior to Gigamon, Tim served in various operational roles at MobileIron, Good Technology, and Symantec.