Elliott Hasiuk

I’m Elliott.

As Partner and Head of Media & Growth, I lead integrated media strategy across paid media, ecommerce, and full-funnel measurement.

Elliott is a Partner and Head of Media & Growth at Part and Sum, where he helps drive growth for category-defining brands including GitHub, Cash App, IMAX, Notion, Mejuri, Bluevine, Life Time Fitness, Ad Age, and PAW Patrol.
With 15+ years of experience building and scaling growth systems, Elliott helped grow Part and Sum’s media practice from its earliest stages into an omnichannel, enterprise-grade operation. He partners closely with founders, executives, and cross-functional teams to align media investment with measurable business outcomes, balancing efficiency, scale, and long-term brand growth across B2C, B2B, and DTC.

A founding member of the growth team, Elliott believes in empowering strong operators and building durable systems. His leadership style blends analytical rigor with creative ambition, fostering teams that challenge assumptions, think strategically, and execute with accountability.

Earlier in his career, Elliott lived in Tokyo, consulting for global brands while launching and scaling ecommerce ventures from $0 to millions in revenue. Before marketing, he toured internationally as a session drummer, collaborating with brands such as Audi and H&M and artists including Pharrell, experiences that continue to shape his culturally fluent, creator-first approach to modern media.
Here at Part and Sum we bolt on to transform digital experiences and grow brands by seeing through the eyes of your customer.

“Once product-market fit is established, media investment should do two things: drive efficient growth and generate actionable insights. In a more privacy-constrained environment, metrics like MER and incrementality testing are critical to understanding true performance."