Meet our Leadership team

Meet our leadership team

Greg Davis

CEO
Greg has served on the Bigleaf Networks' board of directors since 2020. He has a consistent track record scaling businesses and creating enterprise value through revenue growth, operational performance, and strategic acquisitions. Greg’s technology leadership career spans more than 25 years, where he has led multiple companies from start up to over $100 million in annual revenue. Prior to Bigleaf, Greg served as COO at HungerRush, a national leader in hospitality software. Prior to HungerRush, Greg spent eight years as EVP of Sales at Alert Logic, where he led sales, marketing, and other key area of the business.

Mark A. Dirsa

Chief Financial Officer
Mark is a technology veteran, with more than two decades of experience as a financial leader in the industry. Prior to Bigleaf, Mark served as CFO of Garten, CFO of Vendini, CFO of Mobile Complete, CFO of Alexa and in various other finance roles for Keynote Systems. He has negotiated multi-million deals for over 50 diverse domestic and international financings with high-tech companies totaling over $2 billion including sales to Amazon and Keynote Systems. Mark is an avid road and trail runner, completing the NYC Marathon an incredible 14 times.

Jonathan Petkevich

Chief Product Officer
Jonathan brings over 10 years of experience in network monitoring and management technology, serving in both the product management and project management capacities. It is over those years that he has developed a passion for walking products through the conceptualization, development, and launching phases. He’s a true customer advocate and is passionate about reinforcing the customer voice when developing new solutions. When he is not at work, he is usually out exploring State and National parks in his Jeep with his family or cheering on his favorite hockey team.

Andrew Bagnato

VP of Sales
Andrew is a veteran partner and channel leader, spending the past 8 years leading MSP strategy at threat intelligence and security leader Webroot. He first got into this industry absolutely fascinated by the technology. Twenty years later, Andrew values building strong, mutual partnerships with MSP and Channel partners to deliver differentiated technology solutions.

John Hogan

VP of Technical Support
John is a graduate of the University of California at Davis, and earned his J.D. at Northwestern School of Law of Lewis & Clark College. Over the past 20 years, he has held a variety of leadership positions in the indirect channel. John started his career in telecommunications with a 10-year stay at U S West/Qwest Communications, where he spent the majority of his time running the Pacific Region of their Channel Partner program. From there, John spent some time heading Business Development for a local tech start-up and a facilities-based data services aggregator, before joining Comcast as one of the founding leaders of its new Channel Program in 2010. John served as the West Division Director for Comcast’s Program for 3 years, then held the same position for tw telecom/Level 3 for a couple years before joining Bigleaf.

Mike McCullough

VP of Customer Success
Mike brings over 15 years of experience across a wide range of internet technology companies, from business analytics at a 10K+ person search platform, to ad-operations at video and mobile startups, to launching and scaling Customer Success teams at hardware and SaaS organizations. Through a few successful startup exits and more than a few failures, Mike has proven to be an advocate and ally while building cross-functional teams that champion the voice of the customer. When not working he can sometimes be found riding his bike or reading, but more often than not chasing around his special need cats.

Sima Ghafari

SVP of Engineering
Sima brings over 28 years of strategic technical leadership experience in several vertical markets including Enterprise Applications, Telecom, Aerospace, and Medical Device industries. Prior to Bigleaf, she was engaged with several startup to mid-size Medical Device companies as CTO and VP of R&D. She is passionate about technology, innovation and building impactful solutions that address real life challenges. Being an entrepreneur at heart, she has owned multiple businesses and currently serves on the advisory board of a few companies affiliated with the University of California in Irvine. Since 2016 Sima has volunteered as an Innovation, Advisor and Entrepreneur in Residence with UCI where she coaches young entrepreneurs to realize their dreams. Besides technology, Sima is passionate about history, nature, and enjoys outdoor activities.

Susan Fierro

Chief People Officer
As Chief People Officer, Susan is devoted to creating an environment where Bigleaf team members can thrive. She focuses on finding the perfect combination of structure and practicality to attract and retain the most talented employees. Susan has 10+ years of both tactical and strategic Human Resources. Her career started with ADP, where she was helping cook up the product that many HR professionals use today. After 8 years, she was given the opportunity to work for a client and see the other side of the HR world. She continued on to help several different companies with high growth environments whip up their talent management from scratch. Since 2005, Susan has been drawn towards small-to-mid-size entrepreneurial companies, where you know everyone’s name and have personal interactions with everyone on a daily basis. She believes in making all employees feel like they are not just part of a company, they are part of a team.

Susan Fierro

Chief People Officer
As Chief People Officer, Susan is devoted to creating an environment where Bigleaf team members can thrive. She focuses on finding the perfect combination of structure and practicality to attract and retain the most talented employees. Susan has 10+ years of both tactical and strategic Human Resources. Her career started with ADP, where she was helping cook up the product that many HR professionals use today. After 8 years, she was given the opportunity to work for a client and see the other side of the HR world. She continued on to help several different companies with high growth environments whip up their talent management from scratch. Since 2005, Susan has been drawn towards small-to-mid-size entrepreneurial companies, where you know everyone’s name and have personal interactions with everyone on a daily basis. She believes in making all employees feel like they are not just part of a company, they are part of a team.