This PhD investigates collaborative practices and digital tools used by design teams following a user-centered approach to create interactive systems, focusing on how designers document and communicate design rationale across disciplines. Previous research shows that involving diverse actors and discourses stimulates creativity, but miscommunications often occur due to differing priorities, vocabularies, and preferences. Designers must therefore find ways to communicate the rationale behind design solutions, explaining their relevance in specific contexts. Several tools have been proposed for documenting design rationale, but they remain underused due to their tendency to constrain design thinking. This research addresses these challenges by investigating collaborative practices and proposing tools that support documentation around design artefacts in line with current work practices. Three core contributions are presented: (1) uncovering issues in multidisciplinary communication, information sharing, and documentation of design processes; (2) presenting two tools for low-threshold documentation of design rationale and decisions, enabling team communication and creative design through shared workspaces; and (3) demonstrating that our approach allows rationales to emerge organically with artefacts, enabling collaborative idea generation and reflection on past work. The research includes peer-reviewed publications on tracing design artefacts, capturing design decision rationale, untangling design meetings, and highlighting design rationale in collaborative processes. The thesis also acknowledges the support received from academic and industrial partners, as well as colleagues and friends throughout the research. The study explores how design teams work, the tools they use, and the challenges they face in multidisciplinary settings. It emphasizes the importance of documenting design rationale to support traceability and awareness in creative design processes. The research aims to develop tools that facilitate communication and documentation in user-centered design, ensuring flexibility and avoiding constraints on creativity. The findings contribute to understanding how design rationale can be effectively documented and used in ongoing UCD projects.This PhD investigates collaborative practices and digital tools used by design teams following a user-centered approach to create interactive systems, focusing on how designers document and communicate design rationale across disciplines. Previous research shows that involving diverse actors and discourses stimulates creativity, but miscommunications often occur due to differing priorities, vocabularies, and preferences. Designers must therefore find ways to communicate the rationale behind design solutions, explaining their relevance in specific contexts. Several tools have been proposed for documenting design rationale, but they remain underused due to their tendency to constrain design thinking. This research addresses these challenges by investigating collaborative practices and proposing tools that support documentation around design artefacts in line with current work practices. Three core contributions are presented: (1) uncovering issues in multidisciplinary communication, information sharing, and documentation of design processes; (2) presenting two tools for low-threshold documentation of design rationale and decisions, enabling team communication and creative design through shared workspaces; and (3) demonstrating that our approach allows rationales to emerge organically with artefacts, enabling collaborative idea generation and reflection on past work. The research includes peer-reviewed publications on tracing design artefacts, capturing design decision rationale, untangling design meetings, and highlighting design rationale in collaborative processes. The thesis also acknowledges the support received from academic and industrial partners, as well as colleagues and friends throughout the research. The study explores how design teams work, the tools they use, and the challenges they face in multidisciplinary settings. It emphasizes the importance of documenting design rationale to support traceability and awareness in creative design processes. The research aims to develop tools that facilitate communication and documentation in user-centered design, ensuring flexibility and avoiding constraints on creativity. The findings contribute to understanding how design rationale can be effectively documented and used in ongoing UCD projects.