Fluent in English and French (daily written and spoken use) - based in Paris

We are looking for a senior UX/UI designer with strong, hands-on experience in e-commerce, specifically on checkout and payment flows.

This role is not for a generalist UX designer or a pure UI / branding profile.
It is a product-focused, conversion-driven role, where deep understanding of online commerce, performance constraints and user behaviour is essential.

You will work on a B2B SaaS checkout product used by multiple merchants, each with their own branding, technical stack and business constraints.

You will collaborate closely with Product, Data, Engineering and Customer Success to design, test and improve high-impact user journeys.

What you will work on

• Design and optimise checkout, payment and form experiences (mobile-first).

• Improve conversion through UX iteration, A/B testing and data analysis.

• Design UX/UI variants adapted to different merchants, brands and use cases.

• Translate complex constraints (performance, CMS, payment providers, branding rules) into simple, frictionless user flows.

• Contribute to a multi-merchant design system.

• Occasionally support product and merchant communication through clear, structured presentations (internal & external).

  ### This role requires - Must Have

  • 5+ years of UX/UI experience, with significant experience in e-commerce.

  • Proven work on checkout flows, conversion funnels, payment journeys, carts or forms.

  • Strong understanding of:

    • mobile UX,

    • form design,

    • micro-interactions,

    • conversion psychology.

  • Ability to design fast, usable, performance-oriented experiences under real technical constraints.

  • Excellent prototyping skills — Figma is required.

  • Fluent in English and French (daily written and spoken use).

  • A portfolio showing real product problems and outcomes, not only visual design.

    If your experience is mostly branding, marketing websites or visual identity, this role will not be a good fit.

    ### Nice to have

    • Hands-on experience with A/B testing tools (AB Tasty, Optimizely, Google Optimize, etc.).

    • Experience working with analytics and behaviour tools (GA4, Hotjar…).

    • Experience designing for multi-brand or multi-merchant products.

    • Strong collaboration habits with engineers on complex or constrained flows.

• Product & design interview with the Professional Services Director or CTO

• Product vision & collaboration interview with the CPCO, then HR and/or CEO