The paper focuses on the potential of participatory design, digital social innovation, and sustainable human-computer interaction to address urban issues, including gentrification, unsustainable tourism, and social exclusion. Acting in disenfranchised neighbourhoods of Lisbon, the showcased Estampa Colab project combines design ethnography, interaction design techniques, and community engagement to raise sociocultural opportunities and sustainable development. It creatively preserves local identity by blending storytelling, digital pattern creation, and local crafts. The project’s participatory nature actively involves community members in collaboratively developing visual representations of their experiences, empowering them to act as agents of change within their communities. Estampa Colab operates a modular framework influenced by rhizomatic and assemblage thinking, enabling adaptation to local environments and scalability to other urban areas while maintaining cultural and socioeconomic distinctiveness. The iterative development of analogue and digital interactions—including silkscreen and sewing workshops, a co-creation tool for patterns, and an e-commerce-enabled website—emphasises inclusivity, usability, and community benefit. These tools promote collaboration and equitable resource allocation, advancing a post-growth framework that prioritises ecological sustainability and social equality over unrestrained economic growth. The project’s outcomes correspond with critical HCI and post-growth principles, providing a replicable model for addressing systemic urban challenges while leveraging community resilience and sustainable practices.