40-60 Studio

40/60 Studio is an independent UX/UI, UX research and development agency founded in 2016 in Paris, with teams in Paris, Nantes and Lyon. Around 30 people bring three crafts under one roof: user research, design (UX/UI, product, branding) and development (web, mobile, SaaS).

Our name is our method: 40% strategy, 60% production. We frame the problem fast, then we ship. Strategy, design and development sit in the same team: no subcontracting, no hand-offs between agencies.

What we do

• UX research: qualitative and quantitative user research, usability testing (lab or remote), UX and accessibility (RGAA) audits, focus groups, field studies
• Product design & UX/UI: B2B SaaS, ERP, business back-offices, mobile apps, platforms with complex workflows
• Design systems: from tokens to coded components, multi-brand, Storybook, governance
• Multi-device & HMI: from mobile to Smart TV and in-car interfaces (CarPlay, Android Auto)
• Websites & development: Webflow, Next.js, React, headless CMS, native iOS/Android
• Branding & art direction
• Innovation: design sprints, co-creation workshops, AI programs

Why work with us

• Every project is tied to simple, measurable KPIs
• One integrated team, from discovery to production
• Long-term support after launch (CARE / RUN / GROW)
• 200+ projects, 130+ clients across 17 industries, 1 in 3 clients come back, 4.95/5 on Sortlist

Clients include TF1+, France.tv, Arte, Renault, Stellantis, SNCF Transilien, Eiffage, BNP Paribas, LVMH, Heineken, Institut Pasteur, Simplon and Label Emmaüs.

Selected results: +35% conversion for Label Emmaüs, 4x more leads for Simplon, over 1 million micro-transactions in the first weeks of TF1+'s new paid offer.