About Expel

Dave Merkel (aka “Merk”) is the co-founder and Chief Executive Officer (CEO) of Expel.

Dave has been involved in the information security field for nearly 30 years, first as a federal agent pursuing cyber criminals in the era of floppy disks and 2400 baud modems, then as Chief Technology Officer (CTO) and vice president of products at Mandiant. Following FireEye’s acquisition of Mandiant, Dave served as the global CTO of FireEye.

Before Dave’s 10 years as a solutions provider, he spent another decade as a security practitioner. He got his start as a special agent in the Air Force Office of Special Investigations, pursuing cyber criminals and conducting digital forensic investigations, and later as head of AOL’s technical security organization. While at AOL, he created and ran the first incident response capability for AOL and Time Warner, managed software security and policy programs, and built technologies for AOL’s security infrastructure.

He is frequently invited to comment on security-related headlines, and has been featured in news outlets like Fast Company, Bloomberg, The Washington Post, VentureBeat, The Washington Business Journal, Forbes, and numerous security media outlets. Washingtonian has also named Dave on DC’s “Tech Titans” list an impressive six times since 2015, and most recently in 2023.

Justin Bajko is a co-founder of Expel as well as our VP of Strategy and Business Development. It’s Justin’s job to stay close to our customers and partners and make sure that we’re heading in the right direction. He also spends a good bit of his free time fretting about the University of Tennessee’s football program.

Justin has been involved in information security and managed services since just after the turn of the century. Prior to Expel, he was senior director of global service delivery for FireEye’s managed service, FireEye as a Service. Justin was responsible for building and managing FireEye’s security operations centers (SOCs) around the world, including a staff of more than 80 analysts.

Prior to FireEye, Justin was the managing director for Mandiant’s Managed Defense service, one of the industry’s first managed detection and response (MDR) providers. Before that, Justin worked at Symantec where he worked in a number of roles within their managed services business ranging from SOC engineer to senior manager of the global threat response team where he was responsible for detection capabilities, intelligence integration, and customer data ingestion for Symantec’s MSSP customers worldwide.

Justin hails from northeast Tennessee. In his free time he enjoys anything to do with cars (spending an inordinate amount of time making sure his are always clean) or boats, traveling, and playing an embarrassing amount of video games.

Yanek Korff is a co-founder of Expel as well as the company’s Chief of Staff. Yanek focuses on tying together organizational strategy, inter-team mechanics, and internal communications so that our employees can stay focused on serving our customers. That also means that whenever anything looks like it might be about to catch fire, Yanek walks towards it.

Yanek has worked in IT and information security roles for nearly 20 years, beginning as a student help desk technician in a musty basement at the College of William and Mary.

Prior to Expel, Yanek was the vice president of Mandiant’s managed services business, which helped customers mitigate the consequences of security breaches caused by nation states. Yanek established and grew the service to become one of the first follow-the-sun managed detection and response (MDR) providers, accounting for over 30 percent of Mandiant’s revenue. Following Mandiant’s acquisition by FireEye, Yanek served as CTO of FireEye as a Service, FireEye’s managed services offering.

Prior to Mandiant, Yanek was responsible for the majority of AOL’s security infrastructure including authentication, authorization management, public key infrastructure (PKI), and systems that supported incident response, e-discovery, and investigations.

Yanek has a B.S. in Computer Science from the College of William and Mary, and an M.S. in the Management of IT from the McIntire School of Commerce at the University of Virginia. He was the principal author for “Mastering FreeBSD and OpenBSD Security”, published by O’Reilly.

Amy Rossi is our Chief People Officer. She’s leading the charge to make Expel a place where everyone wants to work. That includes how we hire, develop, and take care of our team.

While in college, Amy created her first leadership development program for a summer camp in New York and she’s been building people development programs ever since. She comes to Expel with more than 15 years experience in human resources, talent management, and learning and development.

Prior to joining Expel, Amy was vice president of talent management at MicroStrategy. Before that, she served in human resources and talent management roles at AOL, comScore, Network Solutions and CareerBuilder. She has built talent management functions from the ground up twice and some of her best work has involved developing managers and leaders.

Amy graduated from Cal Poly, San Luis Obispo with a B.S. in Recreation Administration and a Minor in Dance and has completed coursework in adult education at George Mason University.

Cat Starkey’s engineering career spans the past 20+ years, with experience as a software developer, architect, and engineering leader for SaaS companies large and small. Like many engineers, she thrives on problem-solving – whether it’s technologies, businesses, or people. Her varied experience with different workplace cultures has shaped her leadership style and determination to actively provide a healthy work environment — particularly in her efforts to support women and other underrepresented groups in tech. She is currently the Chief Technology Officer at Expel, where she works with other leaders to craft a culture of support, respect, self-care, transparency, and humility.

Greg Notch serves as Chief Security Officer at Expel, where he brings over 25 years of cybersecurity and technology leadership to delivering secure, seamless outcomes for customers. Greg was Expel’s first customer, which gives him a rare, inside-out perspective on the outcomes businesses need to secure their operations and drive growth. With this perspective, he leads Expel’s security operations, internal security, IT, business systems, and customer success teams, and uses practical solutions to solve highly complex technical challenges.

Before joining Expel, Greg spent 15 years at the National Hockey League (NHL), where he played a transformative role in modernizing the league’s technology and security operations. As the NHL’s first Chief Information Security Officer, Greg built its inaugural security program from the ground up, leading a team of 50 across security, DevOps, cloud, and data warehousing. He implemented a zero-trust architecture in record time, drove critical SaaS transformations, and architected scalable solutions using cloud and Kubernetes to support the league’s digital transformation. His efforts safeguarded the NHL’s operations and prepared it to tackle evolving cyber threats in an increasingly complex digital landscape.

Beyond his corporate roles, Greg’s a frequent speaker at security industry events, a guest on popular media and vendor podcasts, and contributes to leading security publications as a freelance writer. He also serves as a venture advisor, guiding startups and investors in tackling today’s toughest security challenges.

Greg’s career also includes leadership roles at Apple, Yahoo, and eMusic, where he solved high-stakes problems like launching eMusic’s infrastructure in just 30 days and managing Yahoo’s East Coast data center operations. Known for his candid, customer-first approach, Greg focuses on continuous improvement and delivering results that matter.

A New York native, Greg values family, community, and time spent perfecting the art of backyard grilling. His ability to blend technical expertise with real-world practicality continues to inspire security leaders navigating the challenges of today’s digital landscape.

Jennifer Lawrence is our Chief Revenue Officer. As CRO, she’s leading the charge to welcome new customers to Expel and help them make space to do what they love through unexpectedly simple security. We’re excited she’s not only bringing her expertise to the team, but also sharing her love of Mondays to help us start every week off right.

Jennifer has over 20 years of experience building and scaling SaaS companies. Before joining Expel, she led both the global Duo Security sales team and the Cisco Secure SaaS team. During her time at Duo, she grew the business from $9M ARR and eight sales people to more than half a billion in revenue and 400 sales people. Clearly we think she’s pretty cool.

Jennifer holds a B.B.A. from The Stephen M. Ross School of Business at the University of Michigan in Finance and Marketing. When she’s not growing companies, you can often find her boxing, pretending to know how to play tennis, and hanging out with her four kids.

Peter Katz joined Expel in 2020 as our Vice President and General Counsel. He’s building our in-house legal team from the ground up. We like that he’s not only bringing his more than 15 years of experience as an attorney to Expel, but also his great sense of humor (kind of a requirement here).

Before joining Expel, Peter was Vice President and General Counsel of Duo Security. During his time as an executive at Duo, he built and led the legal department, serving as a trusted advisor to the management team and Board of Directors. In 2018, his legal strategy was integral during the Cisco acquisition of Duo Security for $2.35 billion.

Prior to Duo Security, Peter was Director and Senior Legal Counsel of AlixPartners, a global consulting firm. He also served as Associate Counsel of Vanguard, one of the world’s largest investment management firms. And before all that, Peter was an Associate in the Corporate & Securities practice at Pepper Hamilton, based in the Philadelphia office.

Peter has a J.D. from the University of Pennsylvania Law School and a B.S. in finance from the University of Florida.

Rick Hasselman is the Chief Financial Officer (CFO) at Expel. He’s responsible for leading and scaling the Expel finance and accounting functions, and working with senior leadership to set and execute company strategy.

This includes managing our operating plan by aligning key business drivers and metrics, and ensuring allocation of resources to support our growth, innovation, and long-term profitability. It also means delivering accurate and timely financial statements and analysis to make informed tactical and strategic decisions. Rick also helps ensure Expel is well capitalized to achieve its goals.

Rick brings nearly 30 years of finance and operational experience to this role, most recently serving as CFO of Podium—a communications and payment platform for local businesses. His career spans audit, tax, and transaction services at PwC; merger and acquisition experience at Google; and growth-stage to IPO knowledge from his time at Sumo Logic.

Rick is a Certified Public Accountant (CPA) with an undergrad degree from Bowling Green State University and an MBA from the Goizueta Business School at Emory University.

When he’s not making sure our books are balanced, you can find Rick enjoying family time with his wife, two sons, and giant yellow lab at their Colorado home.

Yonni Shelmerdine is Expel’s Chief Product Officer (CPO), tasked with leading the company’s product team into its next stage of growth and execution. In this role, Yonni ensures Expel’s product strategy keeps stride with—and even outpaces—our customers’ most pressing security operations challenges, while staying ahead of the emerging threats and attack vectors du jour.

Yonni brings more than 15 years of cybersecurity and product leadership experience to Expel, primarily in high-growth environments. Most recently, Yonni served as vice president of product management at SentinelOne, where he led the company’s endpoint detection and response (EDR) and extended detection and response (XDR) efforts. Prior to SentinelOne, he was a product leader at Cybereason, and held product management roles at Checkpoint and Lacoon Mobile Security.

Yonni was also a commanding officer for multiple teams in Unit 8200 of the Israeli Intelligence Corps unit of the Israel Defense Forces, where he received several awards for his distinguished service.

Yonni holds a Bachelor of Arts degree in economics from Reichman University (formerly IDC Herzliya) and the University of California, Berkeley.

Yonni, a dog person, lives in New York City with his wife, Kat.