Leadership and Management Team

Being a leader in our field comes naturally to us at ATS.

In helping the defense and intelligence communities complete missions, ATS has earned a reputation as a leader for our work in analytic methodology and technological solutions. Our greatest assets—our engineers, developers, and analysts—are the reason why. Thanks to their innumerable and complementary talents, our expertise in analytics, systems, and data makes us a powerful partner in a very uncertain world.

Meet the team behind our industry leadership:

DAVID POPELIER

Chief Executive Officer (Acting)
General Manager, Mission Technology and Solutions Business Unit

David Popelier • General Manager, Mission Technology and Solutions Business Unit

David Popelier is General Manager of ATS’s Mission Technology and Solutions Business Unit. He has more than 20 years of experience serving the national security community, beginning at the State Department as a civil servant and then supporting the IC in both Government staff and contractor roles. Prior to joining ATS in 2020, David managed portfolios of mission-critical contracts for the U.S. Government while at SAIC, LMI, and Oracle; co-founded, grew, and sold the consulting firm FourWinds; and led numerous consulting engagements with executive-level clients on organizational performance metrics, data analytics and visualization, DEI strategy, communications, and research design.

David holds an MBA from George Mason University, a Master’s degree in National Security Studies from Georgetown University, and a Bachelor’s degree in Spanish and History from the University of Wisconsin-Madison. He is a Certified Analytics Professional and PMI Project Management Professional.

YVONNE VERVAET

Chief Growth Officer

Yvonne Vervaet • Chief Growth Officer

YVONNE VERVAET Chief Growth Officer Yvonne Vervaet is ATS’s Chief Growth Officer. A 28-year Defense and Aerospace sector strategist and growth professional, she has served in numerous BD and operational leadership roles including Senior Vice President for Growth & Capabilities and Chief Growth Officer for ManTech International. With ManTech, she led the development of corporate growth strategy and brought new technical capabilities to market. She was also COO of SC3/Cipher and VP of Business Development & Operations for SpecTal (BAE Systems). She has served as a highly respected business development lead for well-known companies such as CSC, EDS, and Northrop Grumman. Her expertise is in accelerated organic growth, M&A planning, and strategic resource alignment, as well as branding and innovation to drive company success. She holds a degree in Business Administration from the Rochester Institute of Technology.

DAVE TIMMONS

Chief Financial Officer

Dave Timmons • Chief Financial Officer

Dave Timmons is the Chief Financial Officer for ATS. He joined the company in 2023, bringing nearly 30 years of financial management experience in both industry and the private sector. Dave most recently served as acting Chief Financial Officer for Empower AI (formerly NCI Information Systems, Inc.). His expertise includes leading mergers and acquisitions and integration of new companies, contributing to company growth through business development, and financial management process improvement. He also brings extensive experience in implementing new accounting standards (including ASC 606 and 842) and liaising with DCAA, DCMA, and external auditors. Dave holds a degree in Business Administration and Accounting from James Madison University.

SHAWN CLARK

General Manager Cyber, Language & Operations Business Unit

Shawn Clark • General Manager Cyber, Language & Operations Business Unit

Shawn Clark

Shawn Clark is General Manager of ATS’s Cyber, Language, and Operations Business Unit. Shawn is ATS’s longest-tenured employee, holding numerous positions and management roles over more than 20 years following his service in the U.S. Army. Shawn’s extensive experience includes supporting IC customers as a Linguist, Targeter, and Program Manager, and prior to his role as BUGM he led ATS’s Mission Technology Division. In addition to his formal leadership roles, Shawn established ATS’s Pillars Program to drive Diversity and Inclusion, promote Philanthropy, support Employee Wellness, and help employee’s take full advantage of their Employee Ownership.

Shawn has a B.S. in Environmental Studies from the American Military University and is a certified PMI Project Management Professional.

APRIL SULLIVAN

Vice President, Business Development

April Sullivan • Vice President, Business Development

April Sullivan is the Vice President of Business Development at ATS, bringing over 16 years of experience in business development within the IC and DoD sectors. She has a proven track record of leading high-performing BD and proposal teams, excelling in both large-scale pursuits and organic growth initiatives. Throughout her career, she has been tapped to establish and grow successful business development and proposal organizations across the industry. She served as the Vice President of Enterprise Proposal Operations at ManTech, where she led a major organizational restructuring within the corporate growth division. Her efforts included implementing streamlined processes, rebranding proposal documents, and defining new roles and responsibilities, all contributing to enhanced team performance and winning strategies. Her unique blend of expertise in both business development and proposal operations provides her with unparalleled insight into the interplay between these two critical functions. Her leadership has also shaped growth organizations at Strategic Intelligence Group and SpecTal. A dedicated leader, she is also a 10-year Air Force Veteran and holds a degree in Multimedia Communications from the Community College of the Air Force.

MARY KHATTAK

Vice President, Human Resources

Mary Khattak • Vice President, Human Resources

Mary Khattak is ATS’s Vice President of Human Resources, leading total rewards, compliance, HRIS, and employee engagement strategy. Mary is also responsible for corporate giving and community outreach through ATS’s Philanthropy Pillar (part of our program of corporate initiatives to best support and engage our employees). Mary is an accomplished human resources executive with more than 25 years of experience with Government contractors and non-profit and for-profit companies. Prior to joining ATS in 2018, Mary was the Human Resources Director at Ace Info Solutions (now part of Guidehouse) and held senior HR positions at SHAPE America, Wolf Trap Foundation, and Wegmans.

Mary holds an MPA from George Mason University and a B.S. in Management from SUNY Geneseo, along with SPHR and SHRM-SCP certifications. She is a member of the Society for Human Resource Management and serves on the board of Dulles SHRM.