• Define and own Cello’s design foundations, including principles, patterns, and a scalable design system • Lead end-to-end product design across core experiences, from early concepts to shipped product • Partner closely with product, engineering, and leadership to shape solutions early and holistically • Design clear, user-centred experiences for end users, growth teams, partners, and developers • Shape how the Cello SDK integrates into customer products and how developers build on top of it • Use user research and product data to inform decisions, validate assumptions, and iterate quickly • Raise the design bar through hands-on work, strong critique, and continuous improvement of how design is done • Ensure a coherent product and brand experience across key customer touchpoints, including the website