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Leadership and Management Team | Meet the Team

MDSL leadership brings years of experience and unparalleled technology expertise.

MDSL Executive Team | Technology Expense Management Experts

Charles Layne
Chief Executive Officer

Charles has spent more than two decades leading growth-oriented technology organizations, most recently serving as President of Signature Technology Group, a Tech Data Corporation. He is a recognized leader in the software technology industry with a keen understanding of the marketplace, product innovation, and developing best-in-class customer solutions. 

During his tenure as CEO and President, he led Signature Technology Group to triple its global revenue and employee base. Prior to 2011, Charles held senior leadership roles at Microsoft within the solution sales organization. He started his IT career as a consultant for IBM and then joined Insight Enterprises where he served as an officer while running the Small & Medium Business Division, as well as the Software Solutions Sales Division. 

Charles is a native of Arizona. He received his Bachelor of Science in Marketing from Arizona State University and holds a Global Leadership Certificate from Thunderbird School of Global Management. Charles serves on the Board of Directors for Arizona-based Student Expedition Program (STEP). He also serves as an Advisor for both Allbound, Inc. and NeoLight Medical. Charles previously served on the Board of Directors for the Arizona Technology Council and the Scottsdale/Paradise Valley YMCA.

Scott Gilbert

Scott oversees Calero-MDSL's ongoing customer operations, which includes ensuring best-in-class service to its growing customer base. With over 20 years of telecom and software experience, Scott most recently served as Chief Information Officer at FirstLight Fiber, where the successful implementation of his systems and process methodology enabled the regional infrastructure provider to scale to nearly five-times its size within a 48-month span via aggressive acquisition and organic growth.

Scott also played a pivotal role in two highly successful private equity transactions while at FirstLight.  Additionally, he has served as Chief Operating Officer of CornerStone Telephone Company and Chief Information Officer of Cleartel Communications. Scott holds a Master of Business Administration degree from Union College and a Bachelor of Science degree in Information Science from Hartwick College.







Andrew Taylor
Chief Revenue Officer

Andrew is responsible for leading both Calero-MDSL's direct and channel sales and customer success programs. By fostering a culture of collaboration and consultation in all phases of customer engagement, Andrew enhances Calero-MDSL's role as a trusted advisor and assures outcomes that exceed customer expectations.

Prior to Calero-MDSL, Andrew was the VP, Sales and Marketing for one of the original Managed Mobility Service providers, Mission Critical Wireless (MCW). Through collaboration and customer engagement, Andrew helped expand MCW’s business from a small regional player to a national player and ultimately a global player, which led to its acquisition by Digital Management Inc (DMI). Once at DMI, Andrew continued his role within DMI’s commercial division as VP, Sales helping DMI achieve Leader status in the Gartner Magic Quadrant.&nbsp; Additionally, Andrew has held multiple leadership positions within AT&amp;T and Verizon Wireless. Andrew attended Miami University of Ohio.

Simon Mendoza
Chief Technology Officer

Simon joined MDSL in 2003 as part of the Development Team after graduating from the University of Cambridge with an MA in Computer Science. He drove the development of a number of key technologies, including MDSL’s e-billing handler architecture, which led to the rapid growth of MDSL’s TEM offering. 

He was instrumental in the design and implementation of the hosting architecture which plays a central part in the delivery of MDSL’s self-service product, and now has overall responsibility for aligning the company’s IT policy with its overall business direction.





Tamara Saunders
Chief Financial Officer

An accomplished financial executive, Tamara has over 20 years of global industry and public accounting firm experience. She currently oversees Calero-MDSL’s Corporate Finance and Human Resources divisions and is responsible for the examination of margins, growth factors, profitability, and cash flow for this multinational technology organization with more than 400 employees. 

Over her career, Tamara has successfully built and led both public and private finance organizations, implemented complex financial systems, and directed various financings, mergers and acquisitions for her respective businesses. Before joining Calero-MDSL in 2017, she served as CFO of Phoenix-based Telesphere and VP of Finance at Vonage. She has also held leadership positions at both iLinc Communications in Phoenix and Arthur Andersen in Dallas and London.

A two-time Stevie® Awards winner, Tamara has also been a finalist for the Financial Executives International (FEI) CFO of the Year Award and been recognized by the Phoenix Business Journal as one of 10 Outstanding CFO’s. She received her Bachelor of Science in Accounting and Master of Science in Accounting from Texas Tech University and is a Certified Public Accountant. A West Texas native, she traded the Texas heat for the Arizona heat and has called Phoenix home since 2002.

Garrett Else
Chief Operating Officer

Garrett Else is a versatile, high-energy executive with a background in finance, IT, and operations and skilled in negotiating partnerships and alliances for enhanced growth. He is a hands-on leader with an extensive background in finance complimented by diverse talents in information technology, project management, operations management, and leadership.

Starting at MDSL in 2017, Garrett lead the successful integration of MDSL and Telesoft and upon conclusion, was appointed to VP of Customer Success. During this time, Garrett transformed the client success team to increase overall client satisfaction and implement client expansion initiatives to elevate MDSL value within the global client base. In October 2019, Garrett was promoted to Chief Operating Officer.

Prior to his work with MDSL, Garrett has held executive and senior financial and operations positions at a range of organizations including Associa, Source HOV, Stream Global Services, Ceridian, and GE Commercial Finance. He holds an MBA in Finance from the University of Texas at San Antonio, a BA in Accounting from Gustavus Adolphus College, and is Six Sigma Green Belt Certified.

David Bliss
EVP, Product Management

David is responsible for Calero-MDSL's strategic product vision, development roadmap and go-to-market activities. David brings a wealth of experience in leading product management teams and taking a customer focused approach to strategic planning. 

Prior to Calero, David led product management for CCC Information Services’ core technology platform where he launched their mobility and artificial intelligence product lines and achieved market-leading status in these areas within 18 months. He also served in a management consultant capacity with PwC and in progressive roles within product management and product marketing while at Accuity.

David holds a Master of Business Administration degree from Northwestern University’s Kellogg School of Management and a Bachelor’s degree in Global Studies with a minor in Mathematics from the University of Illinois at Urbana-Champaign.






Aaron Zeper
VP, Global Customer Demand

Aaron Zeper has 19 years of experience creating and leading highly effective teams focused on profitable market expansion and improved customer experiences. He leads Calero-MDSL’s marketing and new business acquisition strategy, including the advancement of their partner/channel program and overall go-to-market strategy. 

Aaron comes to MDSL from CloudCover, where he served as Executive Vice President of Sales & Marketing. Prior to CloudCover, he served as Vice President of Professional Services, Sales and Marketing with Tech Data Corporation where he was named a CRN Channel Chief in 2017. 




Simon Bone
General Manager, Market Data

Simon joined Calero-MDSL in 2000 and has held various positions within the organization including sales support, account management, global support, and project management for both Market Data and Technology Expense Management implementations. Simon currently heads up the FinTech division utilizing his extensive experience in the market data management business, specializing in analysis and market data cost containment along with a technical understanding of market data delivery technologies.

Prior to joining Calero-MDSL, Simon held positions at Kleinwort Benson, Swiss Bank, UBS and Barclays Capital holding various senior positions in trading room technology and market data management. Simon enjoys playing golf, cycling and is a keen amateur photographer.