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Steve Heymes

MEP Specialist

Headshot of Cassie Withrow

Cassie Withrow

Executive Administrator+Administrative Services Manager

Tyler Tonkin

President+CEO

Professional portrait of GLY employee Andrew Ellis.

Andrew Ellis

Design Manager

Headshot of Pete Abeyta

Peter Abeyta

Hoisting+Rigging Superintendent

Headshot of Danielle Sessler

Danielle Sessler

Senior Project Manager

Headshot of Melanie Cochrun

Melanie Cochrun

Director of Marketing+Communications

Bryce Engen

MEP+CX Manager

Demetrios Stamatakis

Sr. Project Engineer

All People

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2026 GLY Construction, Inc.

Headshot of Cassie Withrow

Cassie Withrow

Executive Administrator+Administrative Services Manager

Excellent customer service comes naturally to Cassie, who approaches every task with a can-do attitude. As Executive Administrator, she enjoys working with people that encourage her and test her limits but allow her to have fun along the way. She manages her time—and many others’—with extraordinary ease and keeps things running like a well-oiled machine. Outside the office, you’ll find Cassie hiking, exploring the city, and when the sun comes out, boating on Lake Washington—all with her husband and pups by her side.

Tyler Tonkin

President+CEO

Since joining GLY in 1998, Tyler has played a pivotal role in shaping the company’s culture and project delivery excellence. Now serving as President and CEO, he brings a collaborative spirit, deep technical expertise, and a strategic mindset to every facet of the business. Tyler’s leadership has guided some of GLY’s most complex and transformative projects—from integrated hospital expansions to urban highrise developments. His commitment to client advocacy and team empowerment continues to inspire innovation and elevate performance across the organization.

Professional portrait of GLY employee Andrew Ellis.

Andrew Ellis

Design Manager

AIA, Assoc. DBIA™

Andrew spent 14 years immersed in his original calling: Architecture. He found that the most enjoyable and rewarding moments occurred while collaborating with builders. Deciding to blend two passions together—design and construction—Andrew now leverages robust VDC tools to better understand, communicate, and help execute a project’s design intent. Simply put, he constructs the building virtually to iron out any wrinkles before it’s built in the field. Outside the office, Andrew can’t get enough of the mountains. The numbers speak for themselves. He’s made his way to the summit of Mount Rainier via 16 different routes!

Headshot of Pete Abeyta

Peter Abeyta

Hoisting+Rigging Superintendent

Headshot of Danielle Sessler

Danielle Sessler

Senior Project Manager

Associate DBIA™

Construction was always part of the plan for Northwest native Danielle, having grown up in a family that owned a contracting business. She took a few detours first, earning a BFA in Metalsmithing and Art History from Central Washington University and working as a Senior Estimator focused on honing her preconstruction services skills. When she landed at GLY in 2013, we quickly recognized her background would be perfect for Design-Build projects. Outside of work, Danielle enjoys hiking, bouldering, climbing—and collecting “odd things that most people scratch their heads over.”

Headshot of Melanie Cochrun

Melanie Cochrun

Director of Marketing+Communications

CPSM

A healthy dose of serendipity led Melanie from the Peace Corps third world to the A/E/C integrated world, where she discovered a love for working with the people behind the concrete. Nearly 20 years later, she is contributing and receiving ideas and inspiration for marketing, communicating, and developing business as the Director of Marketing + Communications at GLY! A self-described thinker, linker, and obstacle shrinker, Melanie likes to approach her work with these three questions: Who is our audience? What do they need? How can we reach them and develop trust?

Bryce Engen

MEP+CX Manager

LEED AP BD+C, BCXA CCP

Bryce is a mechanical systems and commissioning expert and a self-described Swiss army knife. He gets involved during preconstruction assisting with MEP scopes of work. During construction, he becomes hyper focused on QA/QC processes and procedures. On the back end of the job he develops closeout and inspection schedules and plans for startup and commissioning. He is a passionate alumnus of Washington State University, where he studied Construction Management, and minored in Business. His wife, two kids, two dogs, and Macaw parrot keep life busy but fun. Their latest achievement? Building a house together!

Demetrios Stamatakis

Sr. Project Engineer