Leadership

The Apex leadership team consists of experienced individuals with an exceptional ability to combine their roles as consultants and technologists for our clients’ benefit. They bring a natural passion and innate curiosity to solving problems.

• Manuel Mattke, Chief Executive Officer
  
• Stephanie Liu-Barnes, Director of Consulting Services
  
• Brett Holt, Director of Engineering
  
• Kellie Johnson, Director of Finance and Administration

Manuel Mattke – Chief Executive Officer

“At Apex we truly live in two domains: we solve many daily operational business problems that hinder the performance of organizations that make the world a better place. And we do this by applying well-designed technology creatively, in the right places. That’s our passion and our business.”

Manuel leads the Apex team and established the committed Apex culture. Manuel brings over 20 years of experience in, and much passion for, using technology to deliver improved effectiveness. He relentlessly drives the Apex focus on solving problems instead of providing inputs, and on candid, honest communication with Apex colleagues, clients and vendors.

Manuel’s expertise with systems architecture, project management, application development and strategic technical consulting coupled with his high energy and passion make him a great asset to our clients. Prior to launching Apex 8 years ago, Manuel worked as Vice President and Treasurer at the Rudolf Steiner Foundation, a global community foundation and leader in non-profit finance.

Manuel graduated Magna Cum Laude and Phi Beta Kappa with a BA degree in Philosophy from Haverford College in Pennsylvania.

Stephanie Liu-Barnes – Director of Consulting Services

“There is nothing more rewarding than the moment when a client says, ‘we hadn’t thought of that,' and are excited to see the improvements one of our solutions can provide. I strive to help my clients work ‘smarter’ and do whatever it takes to get us there.”

Stephanie leads consulting engagements that can include assessing business processes, overall operational effectiveness throughout an organization or effectiveness within a specified team or area. With almost 10 years of experience working with business process consulting, information systems and technology consulting, she provides a wealth of background for these complex engagements.

Stephanie has worked on projects that include operational effectiveness evaluations, team-specific reviews, business process assessments, executive dashboards, laboratory information management systems, workflow and asset management applications, human resource solutions, enterprise-level contract management systems, and more.

Prior to joining Apex in 2002, Stephanie worked for Accenture on technical projects for clients such as washingtopnpost.com and Iridium along with a variety of other organizations.

Stephanie received dual BSE degrees in Biomedical and Electrical & Computer Engineering from Duke University.

Brett Holt – Director of Engineering

“I am very happy to be a part of such a creative, technically adept organization. The team thinks things through and really pushes the envelope in terms of how we approach and solve a problem. There is no "one size fits all" mentality.”

Brett leads the engineering phase of our projects, during which he and his team turn application designs into fully functional, tested and deployed solutions. Brett joined Apex in 2007 with a background of implementing mission-critical solutions for a variety of government and commercial clients. In addition to dynamic web development, he has engineered software for applications as diverse as spacecraft data systems, medical diagnostic devices, and industrial robotics. His professional interests are in the areas of software architecture and design, and he is passionate about software process improvement.

Brett brings 20 years of software development, interface design, and process design experience from organizations like Advanced Technology & Research Corp, Broadsoft, Inc., and IGEN International.

Brett received his BS in Electrical Engineering from Rice University and his MS in Computer Science from Johns Hopkins University.

Kellie Johnson – Director of Finance and Administration

“Working at Apex is both challenging and fun. The energy of the team and the 'can-do' attitude is refreshing and contagious. I enjoy working with the whole team as well as with our clients. I work hard to ensure that our internal processes run smoothly and efficiently and that, collectively, we help our clients reach their goals.”

Kellie’s primary focus is maximizing Apex’s fiscal resources through budget planning, project coordination and efficient billing processes. Additional responsibilities include the full spectrum of human resources and administration such as employee compensation and benefits as well as oversight of the celebrated Apex office space. Kellie brings eighteen years of experience to Apex.

Prior to joining Apex in 2002, Kellie was a Financial Manager for the National Committee to Preserve Social Security (NCPSSM) and Medicare where she was responsible for the committee's fundraising cash management operation.