The Challenge
When I joined the Costco.com team, the checkout experience was desktop-only and difficult for mobile users. The four-step flow surfaced uncommon tasks like shipping to multiple addresses as primary actions, creating unnecessary friction for most users.
Each change carried real risk. Millions of customers used this flow across multiple markets, making clarity and efficiency critical.
Research & Discovery
I analyzed competitors, reviewed academic studies, and partnered with engineering to understand the technical constraints that would shape our solution. I created detailed user flows documenting the current four-step process and proposed wireframes showing streamlined three-step and two-step versions that prioritized the most common user needs.
Ideation & Testing
To prepare for testing, I facilitated ideation sessions with a team of 10 designers, guiding prototype development and defining a hypothesis for us to test against.
To validate our approach, I planned and executed a usability study with 30 participants across mobile and desktop. We tested two potential checkout frameworks: one with two pages and one with three. We found no meaningful difference in drop-off between the two approaches.
The three-page model was technically simpler to build and gave us more flexibility to tailor checkout experiences across global markets. With no measurable increase in friction, we recommended the three-page model as the optimal balance of usability, technical feasibility, and global flexibility. We presented our findings to executive leadership and aligned on the three-page framework as our path forward.
The confirmation page in mobile view.
Design & Execution
The final design delivered a fully responsive, mobile-first checkout that simplified tasks for the majority of users while keeping less common actions accessible through progressive disclosure. We reduced the flow from four steps to three, reorganizing content around the tasks most customers complete on every purchase.
I designed the Order Confirmation page across all devices, ensuring consistency and polish throughout the flow.
Impact
The redesign launched successfully, receiving praise from both users and executives. Over the following two fiscal years, Costco’s online sales grew by $1.3B, increasing from $3B to over $4.3B. Improvements to the checkout experience were cited in external reporting as a contributing factor in that growth. This project demonstrated how user-centered research, rigorous testing, and collaborative ideation can create durable, high-impact solutions.
