When Heidi O’Neil describes her career trajectory, she refers to it as “the long and winding road.” It’s a fitting description for a professional journey that began in public accounting in the 1980s and has since spanned public and private industries, local government, and now a senior leadership role at Denver International Airport (DEN), an enterprise fund of the City and County of Denver.

In 2025, O’Neil participated in Eno’s Transportation Senior Executive (TSE) program as part of that ongoing journey. Having taken part in leadership development programs earlier in her career, she approached TSE not as an introduction to leadership concepts, but as an opportunity to step back, reflect, and engage more deeply with peers from across the transportation sector.

Stepping outside the airport environment and engaging with leaders from rail, freight, and other modes reinforced the interconnected nature of the transportation system and clarified where airports fit within the broader ecosystem. The experience offered a wider lens – one that complemented her existing leadership experience and added nuance to how she thinks about her organization and the industry as a whole.

Building a Career Across Sectors

O’Neil’s career had prepared her well for this multimodal perspective, shaped by experience across public accounting, private industry, and government.

She attended the University of Denver, where she earned a Bachelor of Accounting degree. Reflecting on that time, she notes that accounting was not her first choice; however, in the 1980s, it was one of the emerging professional fields that offered women a clear path forward. Upon graduating, she joined what is now KPMG and began her career in public accounting, working in audit and supporting small- and medium-sized company audit and tax engagements. During this period, she earned her Certified Public Accountant (CPA) license in the State of Colorado, which she has proudly kept active throughout her many career chapters. After working at KPMG for a period of time, Heidi’s career path led into “high technology” industries, and she worked for several companies in this space, leading the accounting functions for these organizations. While much of this work involved corporate accounting, it also included financial planning/budgeting and merger/acquisition activities.

In 2016, O’Neil began to reassess her career trajectory and consider how her experience across private and publicly held companies could translate to roles with a stronger public mission. The complexity and accountability she had navigated in earlier positions ultimately led her toward opportunities in the government sector, where financial stewardship, transparency, and long-term impact are foundational.

She joined the City and County of Denver Auditor’s Office as an appointee, focused on strengthening the financial aspects of the performance auditing function. The role offered a different lens on accountability – one rooted not in shareholders, but in public transparency and service. Through rigorous oversight, collaboration with elected officials and agency leadership, and stewardship of public resources, O’Neil developed a deeper understanding of government operations and a meaningful connection to public purpose.

That experience helped position her well for what came next: a move to Denver International Airport, an organization that sits at the intersection of public ownership and business-like operations.

O’Neil accepted a role as Director of Accounting, marking the beginning of her ascent within one of the most complex transportation enterprises in the country. In 2023, she was promoted to Senior Vice President of Accounting and currently leads a team of more than 30 accounting professionals.

Leadership Perspective Through TSE

As her responsibilities grew, O’Neil began to seek out leadership development opportunities that matched the scale and complexity of her role. While she initially thought an airport-focused program might be most relevant, she found significant value in learning alongside leaders from other modes through TSE.

O’Neil jokes that “TSE found me,” explaining that DEN places a strong emphasis on leadership development and actively encourages employees to pursue opportunities that support professional growth. She credits the airport’s leadership – particularly CEO Phil Washington – for prioritizing programs that invest in employee development and for recognizing the value of cross-sector engagement. After a thoughtful but approachable application and interview process, O’Neil was selected as one of two DEN participants in the 2025 cohort.

Inside the program, O’Neil valued both the diversity of professional backgrounds represented and the depth of the curriculum, which spanned a wide range of leadership topics. Coming into TSE with prior leadership training, she approached the experience with a discerning lens – considering which concepts reinforced her existing approach and where new perspectives emerged.

She highlighted the facilitated breakout sessions and guest speakers as particularly impactful, noting that they encouraged candid dialogue and grounded leadership concepts in real-world experience. One component that stood out was the 360-degree evaluation, which provided a clear view into how her leadership is perceived by others. While the feedback affirmed many of her strengths, it also revealed areas where she could more intentionally close gaps – underscoring the value of reflection at her stage of career.

The program also created space for open and honest conversations about organizational challenges, leadership dynamics, and perception. O’Neil valued the opportunity to share experiences, hear how others navigate similar issues, and translate those insights back to her own organization in ways that resonate.

When asked what advice she would offer to others considering an Eno program, O’Neil was unequivocal. Opportunities like TSE, she noted, are relatively rare, particularly for senior leaders. The application process itself is a valuable exercise, and the chance to pause, reflect, and learn alongside peers from across the transportation ecosystem is not one to pass up.

For O’Neil, the long and winding road has been shaped by a willingness to adapt, learn, and lead across industries and sectors – an approach that continues to guide her work as she helps navigate financial leadership at one of the nation’s largest and most complex airports.

More About O’Neil:

On the personal front, O’Neil is a Colorado native and lives in the Denver area with her husband, a retired educator of nearly 40 years in the Cherry Creek School District, and one of their three adult sons with special needs. Her other two sons are pursuing careers in marketing project management and data analysis, and in public accounting. Outside of work, O’Neil is an advocate for children, teens, and adults with special needs and enjoys running, biking, hiking, traveling, and staying active.