Board of Directors

Providing insight on strategy and direction with integrity and dedication

People Didier Bouillard

Didier Bouillard

Chief Executive Officer

Didier Bouillard serves as the CEO of AxiomSL and Calypso following the merger of the two companies in July 2021. Didier joined Calypso as CEO in April 2018 and is based in London. Prior to Calypso, Didier served as CEO of Ullink, global provider of connectivity and trading services, beginning early 2015. The main objective of the assignment was to merge NYFIX, acquired by Ullink late 2014, and to transition the overall group from a founder led business into a professionalized Private Equity owned business. After experiencing multiple years of steady growth of revenues and profits Ullink was successfully sold to Nordic Capital backed Itiviti. Prior to Ullink Didier was Executive Vice President at Sungard Financial Systems (now part of FIS) and operated a substantial part of the Capital Markets and Electronic Trading division, playing a key role in the global distribution.

Didier started his career in the 1990’s and has been part of successful entrepreneurial ventures providing leadership as partner, Managing Director and CEO (Ubitrade, Capital Fund Management, Fermat) where he gained extensive knowledge of the capital market industry as well as a true international exposure.

Didier graduated from Ecole Nationale des Ponts et Chaussées in 1988.

Alex Tsigutkin

Alexander Tsigutkin

Founder and Director

Alexander Tsigutkin is a member of the Board of Directors. Alex is the founder of AxiomSL and served as its CEO from 1991 to the merger with Calypso in 2021.

As the founder of AxiomSL, Alex designed the original framework for AxiomSL’s solutions, and invented and patented its dynamic approach to managing data for risk management and regulatory reporting applications.

Prior to founding AxiomSL, Alex was an independent consultant to top-tier international banks and financial institutions, advising senior management in banking operations and database engineering.

Alex holds a B.A. in computer science from Yeshiva University. He also attended the Graduate Computer Science Program at the Polytechnic Institute of New York University.

Board of Directors Holden Spaht Managing Partner

Holden Spaht


Holden Spaht is a Managing Partner at Thoma Bravo. Based in San Francisco, he joined the firm in 2005. Holden is responsible for finding and executing new deals, monitoring and growing the portfolio as an active board member, and helping to manage the firm. Previously, he was with Morgan Stanley Capital Partners in London, Thomas H. Lee Partners in Boston, and Morgan Stanley in New York. Additionally, he is a member of the Tipping Point Community Leadership Council and Trustee of Schools of the Sacred Heart San Francisco. Holden was a Fulbright Scholar and earned his BA degree in Economics at Dartmouth and his MBA at Harvard Business School.

AxiomSL Board of Directors Charles Goodman Operating Partner

Charles Goodman


Charles Goodman is an Operating Partner at Thoma Bravo. Charles has more than 30 years of experience building profitable businesses. Most recently he served as CEO of PowerPlan, a Thoma Bravo portfolio company that sold to Roper Technologies in 2018. Prior to joining PowerPlan in 2015, Charles was CEO of P2 Energy Solutions. As CEO, he executed multiple market strategies and led three acquisitions to expand the solution portfolio from the back office into operations, while steadily growing P2’s presence across the globe. At Ventyx, he served as COO and was instrumental in developing new global markets across six continents. In addition to helping companies expand, Charles has a passion for transforming organizations by focusing on employee culture and the customer experience. During his tenure at Atmos Energy, where he was EVP, Corporate Operations, he experienced first-hand how these factors influenced the company’s success. Charles graduated from Texas Tech University with a BS degree in Engineering.

AxiomSL Board of Directors Kristin Nimsger

Kristin Nimsger


Kristin Nimsger is an Operating Partner at Thoma Bravo. She has more than 20 years of experience driving outsized growth in software and technology companies. Kristin was President of Kroll Ontrack, where she ran the business from start-up to more than $200M in seven years. Kroll Ontrack operated in 23 countries with 1500+ employees, and the company was sold to Providence Equity Partners in 2010. Additionally, she was General Manager of the litigation software division of Thomson Reuters. Kristin also served as CEO of two Vista Equity Partners portfolio companies: MicroEdge, which was sold to publicly traded Blackbaud (Nasdaq: BLKB in 2014), and Social Solutions Global. During her time with Social Solutions, Kristin led the negotiation of and partnership with Ballmer Group, which included a $59M investment from former Microsoft CEO Steve Ballmer, who joined the company’s Board of Directors. Before joining Thoma Bravo, she most recently served as a Senior Advisor, Private Equity to Vista Equity Partners. Kristin has a BA from the University of Minnesota, a Juris Doctorate from William Mitchell College of Law, and a Certificate in Management and Leadership from MIT Sloan School of Management.

AxiomSL Board of Directors Erik Akopiantz Operating Partner

Erik Akopiantz


Erik Akopiantz is an Operating Partner at Thoma Bravo. He brings a combination of entrepreneurial, operational, strategic and transaction expertise across a variety of industries spanning start-ups to Fortune 500 organizations. Erik’s prior experience includes serving as a Board member for Bomgar, Operating Advisor for GHX, SailPoint and DigiCert, Chief Financial Officer for Roadnet Technologies, Inc., Chief Operating Officer for Paranet Solutions, LLC, CEO for Digital Reach, and various finance positions for The SABRE Group. He earned an MBA from Rice University and a BS degree in Finance from the University of Vermont.

AxiomSL Board of Directors Jamie Hutter Vice President

Jamie Hutter


Jamie Hutter is a Vice President on the Flagship team at Thoma Bravo. Based in San Francisco, he joined the firm in 2014. In this role, Jamie focuses primarily on application software investments. Prior to Thoma Bravo, he worked in investment banking at Morgan Stanley. Jamie earned his BA with Honors in Science, Technology & Society at Stanford University and is a member of the NextGen Leadership Council for the Boys & Girls Clubs of San Francisco.

AxiomSL Board of Directors Brian Jaffee Principal

Brian Jaffee


Brian Jaffee is a Principal on the Flagship team at Thoma Bravo. Based in San Francisco, he joined the firm in 2014 as a Vice President. Prior to joining Thoma Bravo, Brian served as an Associate and Senior Associate at Veritas Capital. Prior to joining Veritas in 2009, he worked as an Investment Banking Analyst in the Leveraged Finance Group at Merrill Lynch, where he originated structured and executed leveraged loan and high yield bond financings for leveraged buyouts, strategic acquisitions, and recapitalizations across a wide range of industries. Brian holds a BS degree, magna cum laude, in Finance from Miami University and an MBA from University of Chicago.

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