Design System Designer - Mercari

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Design System Designer - Mercari

• Employment Status:　Full-time
• Work Hours: Full Flextime (no core time)
• Office: Roppongi

For more details, see the Overview of Our Positions section on our Careers site.

About Mercari

Circulate all forms of value to unleash the potential in all people

"What can I do to help society thrive with the finite resources we have?" The Mercari marketplace app was born in 2013 out of this thought by our founder Shintaro Yamada as he traveled the world. We believe that by circulating all forms of value, not just physical things and money, we can create opportunities for anyone to realize their dreams and contribute to society and the people around them. Mercari aims to use technology to connect people all over the world and create a world where anyone can unleash their potential. For more information about Mercari Group’s mission, see Mercari’s Culture Doc

Organization/Team Mission

Mercari Engineering Principles

Mercari Engineering Principles are a shared understanding that serves as the foundation of engineering beliefs and behavior at Mercari. The Engineering Principles are designed to complement the organizational identity (Mercari’s mission, values, and culture) from an engineering viewpoint.

These principles ultimately help us achieve Mercari’s mission by defining the ideal state we seek to realize in the long term.

• Passion For The Product
• Grow Together
• Solve Through Mechanisms
• Collaborate Openly

For more details, please see the following link:

• Engineering Culture

In the Design system team we are looking for a hands-on Design System Designer to support the creation, evolution, and governance of our design system across multiple product teams. This role blends UI craft, systems thinking, and strong collaboration with designers, engineers, and brand partners to create scalable, accessible, and cohesive experiences.

See here for more information about our mission and values.

Work Responsibilities

• Design, refine, and maintain reusable UI components, patterns, and guidelines for the design system.
• Define and evolve design tokens, including spacing, color, and typography.
• Ensure platform consistency across Web, iOS, and Android.
• Drive accessibility and inclusive design practices to support WCAG-aligned standards.
• Work closely with engineers to ensure accurate component implementation and maintain parity between design and code.
• Partner with product designers to support design system adoption, identify gaps, and ensure alignment across teams.
• Collaborate with brand and product design teams to ensure cohesion between brand identity and system architecture.
• Create and maintain clear documentation, usage guidelines, and examples.
• Establish and improve contribution, versioning, and change-management processes for the design system.
• Lead workshops, training sessions, and onboarding to support effective use of the design system.
• Audit product experiences to identify inconsistencies and propose system-driven solutions.
• Reduce design and component fragmentation across surfaces.
• Continuously evaluate design system performance and future needs.
• Explore and experiment with AI tools such as code-assist tools and generative UI exploration to enhance system creation, documentation, and scalability.
• Identify opportunities where AI can accelerate component design, audits, token generation, and documentation.
• Promote best practices for integrating AI into the design and development workflow.

Unique Challenges

• Balancing scalability, consistency, and usability while supporting multiple product teams and platforms.
• Driving alignment across designers, engineers, and brand partners while evolving system governance, adoption, and implementation quality.

Qualifications

• Required Experience/Skills
• 5+ years of experience, mainly in a design system-focused role.
• Strong portfolio demonstrating systems thinking, component design, and visual craft.
• Deep expertise in Figma, including variants, Auto Layout, tokens, and libraries.
• Experience working closely with front-end engineers.
• Strong understanding of accessibility, responsive design, and multi-platform workflows.
• Excellent communication skills and the ability to explain system logic clearly.
• Business-level English.

• Preferred Experience/Skills
• Familiarity with front-end technologies such as React component libraries, CSS architecture, and design token pipelines.
• Experience building multi-brand or multi-platform design systems.
• Interest in and practical experience leveraging AI tools to improve design efficiency and system scalability.
• Business-level Japanese, written and verbal.

• Language
• Japanese: A2 (preferred, optional)
• English: B2 (required)

For details about CEFR, see here.

Learn More About Mercari Group

• Careers site:
• Mercan:
• Social media: X / Linkedin

Recruiting at Mercari

At Mercari Group, we value empathizing with and embodying the mission and values ​​of the Group and each company. To promote the creation of an organization that maximizes the total amount of value exhibited by all members, we would like to understand the experience and skills of each candidate as accurately as possible.

Recruiting cycle at Mercari Group

• Application screening
• Skill assessment: For engineering positions, you will be asked to complete a skill assessment on HackerRank or GitHub. For non-engineering positions, you may be asked to complete an assessment depending on the position. (The timing of the assessment may coincide with the interview process.)
• Interview: The number of interviews may vary depending on the position.
• Reference check: We will ask for online references around the timing of the final interview.
• Offer: Offers will be determined carefully in consideration of the final interview and the reference check.

Learn more about our recruiting process here.

Equal Opportunity Hiring

Here at Mercari, we work to realize a world in which no one’s potential is limited by their background and everyone has the opportunity to freely create value. We also firmly believe that a mindset of Inclusion & Diversity is essential for us to achieve our mission.

This, of course, extends to our hiring practices as well. Mercari is committed to eliminating discrimination based on age, gender, sexual orientation, race, religion, physical disability, and other such factors so that anyone who shares our mission and values can join us, regardless of their background. For more details, please read our I&D statement.

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