Her Story
About Jillian
Jillian Byrnes is Managing Director and Head of People at Quadrant Advisory, but her path there wasn't a straight line, and she'd be the first to tell you that's the point.
She started in public accounting in 2008, earning her BS in Accounting from SUNY College at Old Westbury and passing her CPA exams in 2016. Her early years were spent around tax compliance for small businesses, and high-net-worth individuals on tax and financial strategy, learning structure, precision, and how to ask the second question. Because simple and shallow sound the same until you do.
The defining chapter came when she joined a growing company as its very first employee. She built the tax practice from scratch, then stepped into the role of Head of People and Culture/Chief People Officer, functioning as de facto COO through the company's highest-growth years. She scaled the team from a single hire to more than 40 people, built the cultural infrastructure that made that growth sustainable, and guided people operations through due diligence and a successful acquisition. She learned what it takes to build something from nothing. Then she learned what it takes to rebuild yourself when the chapter ends.
After the sale, Jillian went through what she calls her rebuilding season — the kind that strips everything down to the studs. She emerged with a conviction that now anchors her work: mistakes are lessons, not life sentences, and whatever you're not changing, you're choosing. She returned to the professional world in 2025 and stepped into her current role at Quadrant Advisory that June, where she leads people strategy, culture transformation, and the full employee lifecycle — recruiting, onboarding, performance, and organizational design, with a rare combination of financial acumen and genuine human insight.
Her contributions earned her recognition as a featured representative for Huntington, New York, through Influential Women in 2026. She also has started a passion project, Phoenix, Hold My Coffee, a Substack about transformation, leadership, and what it actually takes to begin again.
Outside of work, Jillian keeps herself humble the best way she knows how: as a perpetual beginner. She practices yoga, plays piano, and is learning French, badly, then better, which is rather the point. She's an avid traveler who has volunteered in wildlife conservation in South Africa, and she'll take a trail, a garden, or an ocean over a screen any day. She lives on Long Island with her husband and their two dogs, Abby and Sully. Proof that her best builds are the ones that last.
Her Interview
Ten minutes with Jillian
01What do you attribute your success to?
Two things, and they took me years to hold at the same time. The first is my village, the mentors and colleagues who believed in me before I believed in myself, especially the founder, who saw a leader in me back when I only saw a tax accountant. The second took longer: learning to give myself credit. For a long time, I attributed everything to luck or other people. Now I know that the growth was mine. Someone can open the door for you, but you're the one who has to walk through it — and keep walking when it gets hard.
02What’s the best career advice you’ve ever received?
Two pieces have stayed with me. The first came from client service: never over-promise and under-deliver — your word is the only currency that doesn't devalue. The second came from a founder and mentor: zoom out and think big. When you're deep in the details, everything feels urgent, and nothing feels possible. Altitude changes both.
03What advice would you give to young women entering your industry?
Don't hide. I spent too many years making myself smaller in rooms I had every right to take up space in, and I can tell you exactly what smallness costs... It's more than anyone tells you. Find your voice early. Trust that you belong in the room, even when everyone in it seems more powerful or more experienced than you. They were beginners once, too. The difference between the women who rise and the women who wait is rarely talent. It's permission, and the only person who can grant it is you.
04What are the biggest challenges or opportunities in your field right now?
The biggest challenge in people's work right now is emotional complexity at scale. Employees and clients are carrying real weight. Economic uncertainty, geopolitical tension, genuine anxiety about AI and job security — and they bring all of it to work, because there's nowhere else to put it. The old playbook of policies and perks can't touch that. But that's also the opportunity: organizations that build real emotional intelligence into how they lead and make people feel safe, seen, and heard won't just retain talent. They'll become the places everyone else's talent leaves for.
05What values are most important to you in your work and personal life?
Presence over performance. I care more about enjoying the journey than racing to the outcome. I've stood at enough finish lines to know the medal isn't the point. Active listening matters deeply to me: simple and shallow sound the same until you ask the second question. And I try to show up fully for the people around me, in the highs and the lows, because I know what it means when someone does that for you, and I know what it costs when no one does.
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