DESIGNVADMarc Vadurel
Senior Product Designer & Design Engineer

Design System RATP.

Creating a shared language to unify eight of business applications.

When I joined the project, each squad was designing interfaces independently, leading to major UX/UI inconsistencies and significant design debt across the ecosystem.

My role was to help define the foundation of a Design System that could align teams, improve consistency, and accelerate product delivery.

Product Strategy Design System Governance Usine Digitale
01 / Scoping

Unifying a heterogeneous landscape

The first step was to understand the complexity of the ecosystem.

I conducted a strategic analysis of 8 internal business applications, mapping existing UI patterns and squad practices.

This work helped identify key inconsistencies and define the objectives of the Design System:
• visual consistency
• faster product delivery
• stronger brand cohesion

RATP Scoping Miro
02 / Co-construction

Aligning 32 stakeholders

Design systems only succeed when teams adopt them.

I facilitated 7 workshops bringing together designers, developers, and product stakeholders to co-create the foundations of the system.
These sessions helped align 32 stakeholders around a shared visual language and a common approach to UI design

Stakeholder alignment
03 / Maturity

3 levels of Design System maturity

To structure the initiative, I defined a Design System maturity model.
Level 1 → UI consistency
Level 2 → Reusable components
Level 3 → Shared product language and scalable system

This framework helped teams understand the long-term vision and progressively adopt the system.

Maturity Pyramid
04 / Fundamentals

The core foundation

The Design System was built on five fundamental pillars:
Colors
Typography
Size & spacing
Iconography
Naming conventions

These elements formed the universal foundation used across the ecosystem.

RATP Style Fundamentals
05 / Delivery

MVP delivered in 8 weeks

The initial Design System foundation was delivered in 8 weeks.

It included:
• a structured Figma library
• reusable UI components
• clear design guidelines

This first release helped eliminate major UI inconsistencies and provided a shared foundation for future product development.

RATP Figma and Storybook
06 / Synthesis

The Full Scope

Harmonizing 8 of business applications required more than a visual framework.

The Design System was built as a shared language across teams, supported by a collaborative governance model where product squads could propose components that were reviewed and integrated into the system.

This approach improved consistency, reduced design debt, and accelerated product delivery across the ecosystem.