Once For All is a high-growth, cloud-based, SaaS subscription business. Our technology helps our customers to manage their supply chain governance, risk management and compliance. We work across public and private sector and have over 250k customers across the UK across 20 different sectors including construction, transport, retail, hospitality education, facility and property management, manufacturing, local and central government. Role Summary : We are looking for a Mobile App UX/UI Designer(Contract role for 6 months) to lead the design and user experience of our upcoming marketplace app. You will work closely with product managers, developers, and researchers to ensure the app delivers a seamless, user-friendly experience. Your focus will be on mobile-first design, usability, and a clean UI that enhances engagement and conversion. Job Responsibilities: Design user-centered experiences for the marketplace mobile app, from concept to high-fidelity UI. Develop wireframes, interactive prototypes, and user flows to illustrate design ideas. Ensure designs are mobile-first and optimized for iOS and Android platforms. Collaborate with user research teams to gather insights and refine designs based on feedback. Work within and contribute to Once For All’s design system, ensuring consistency across products. Partner with developers to ensure smooth handoff and implementation of designs. Advocate for accessibility and best UX/UI practices in mobile design. Knowledge, Skills, Experience and Qualifications: 5 years of UX/UI design experience, with a focus on mobile apps. Strong portfolio showcasing marketplace, SaaS, or B2B mobile product designs. Proficiency in Figma, including components, variables, tokens, and prototyping. Experience in mobile-first and responsive design, following iOS and Android UI guidelines. Knowledge of user testing, feedback loops, and data-driven design decisions. Familiarity with design handoff tools and collaboration with developers. Strong communication skills and ability to present design rationale effectively. Nice to have: Experience designing for B2B marketplaces or procurement platforms. Understanding of motion design and micro-interactions for app engagement. Familiarity with construction industry software or compliance-related platforms. Knowledge of front-end development principles (HTML, CSS, React Native) for better collaboration. Why Join Us? Work on a high-impact marketplace app for a leading SaaS platform in the construction industry. Fully remote and flexible freelance contract. Competitive rates with the opportunity to shape the mobile experience of a growing platform. Collaboration with a talented and passionate cross-functional team. If you're excited about shaping a best-in-class mobile UX/UI for a new marketplace, we’d love to hear from you