Title: Principal
Company: Windward Mark Advisory CPA PLLC
Location: New York, New York, United States
Mark Diffley, Principal at Windward Mark Advisory CPA PLLC, has been recognized by Marquis Who’s Who Top Executives for dedication, achievements and leadership in Financial Management.
Mr. Diffley has established a distinguished career in financial management, business strategy and building finance operations for technology companies and startups, spanning three decades. As the principal at Windward Mark Advisory CPA PLLC since 2023, he has led the firm with a focus on integrating the latest technology and software developments into client solutions. Mr. Diffley’s responsibilities include engaging with a diverse client base to understand their unique challenges, consulting with engineers and startups, building effective teams and processes, measuring performance outcomes and fostering collaboration to drive business success. Under his leadership, Windward Mark was incorporated as a professional limited liability company in December 2024.
In addition to his role at Windward Mark Advisory Group CPA PLLC, Mr. Diffley has served as an expert with Primary Venture Partners since 2024, providing strategic guidance to emerging businesses. That same year, he also served as a financial advisor for Etna Lobas in 2024, contributing his expertise to support the organization’s financial operations.
With a 30-year career in the industry, Mr. Diffley has had the opportunity to work for several notable organizations, consistently advancing in his roles. From 2021 to 2023, he was the interim chief financial officer at Parity Technologies, a London-based technical contributor to Polkadot. Previously, Mr. Diffley served as the chief financial officer for both Independence USA PAC and Hawkfish LLC from 2020 to 2021. He also served as the senior director at Geller & Company during the same period.
Mr. Diffley’s earlier experiences also included serving as the head of finance at Blink Health between 2018 and 2019, as a controller at SeatGeek from 2017 to 2018, and as the senior vice president and global controller at KAYAK Software between 2010 and 2017, where he managed international finance operations and compliance across multiple jurisdictions. His tenure at Take-Two Interactive Software Inc. spanned from 2005 to 2011, during which he held several leadership roles, including director of operational accounting, senior director of global finance projects and acting financial director. In these capacities, Mr. Diffley played a pivotal role in streamlining global finance functions and supporting corporate growth initiatives.
Earlier in his career, Mr. Diffley held financial roles with CBS Corporation, Disney ABC Television Group under Walt Disney, and PricewaterhouseCoopers, dating back to 1995. Throughout his career, he has been recognized for transforming the traditional accounting role into an engaging and fulfilling career path.
Mr. Diffley’s academic foundation includes a Bachelor of Science in accounting from Miami University in Oxford, Ohio, earned in 1995. He soon became a certified public accountant through the New York State Education Department in 1998. Influenced by his father and brothers, who are also accountants, Mr. Diffley initially considered architecture but chose accounting due to his father’s advice.
Active in his professional community, Mr. Diffley is a member of the American Institute of Certified Public Accountants. Beyond his professional pursuits, he is deeply committed to civic engagement and community service. Since 2022, Mr. Diffley has served as the treasurer of Open House New York, a nonprofit dedicated to promoting public understanding of New York City’s built environment through annual festivals and year-round programming. Additionally, since 2024, he has volunteered with RefugePoint, an organization initially focused on resettling refugees in Nairobi that now supports immigrants globally through employment assistance, family reunification and medical care programs.
Highly regarded for his expertise in financial management and business strategy, Mr. Diffley attributes his professional success to curiosity and a willingness to embrace new experiences. He also believes that connecting with individuals and learning from them has been central to his achievements. Looking ahead, Mr. Diffley aims to help others recognize how technology can enhance lives and transform work environments while fostering healthy democratic participation through community involvement and volunteering efforts.
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