Background: Background: The Symptom iNput Clinical (SYNC) system was developed to enhance the timely reporting of Head and Neck Cancer (HNC) symptoms and to ensure that high-risk patients receive faster diagnoses. A key feature of the system is a digital questionnaire co-designed with patient representatives to accommodate varying levels of digital literacy. The system integrates a validated algorithm that assigns risk scores to categorise cases as low or high risk, and a dashboard that supports clinicians by providing them with patient reports. However, the development process encountered challenges that necessitates a systematic evaluation of the process, roles, and experiences of team members. Objective: Objective: This study aims to identify challenges faced during development, how these challenges were addressed, and the implications for future digital health innovations. Methods: Methods: A qualitative single-case study approach will be employed, focusing on individuals involved in the SYNC system’s development. Participants will be selected using a combination of purposive and snowball sampling to ensure diverse perspectives, using meeting minutes and recommendations from key stakeholders. A total of 8 to 12 participants will be interviewed, representing clinical, research, and IT roles. Data collection will involve semi-structured interviews which will be conducted through Microsoft Teams. The interviews are expected to last between 40–60 minutes each. These interviews will be audio-recorded, transcribed, and analysed using framework analysis in Dedoose. Actor-Network Theory (ANT) will guide the analysis by mapping interactions between human and non-human actors, such as developers, clinicians, and technological tools, to understand how they influenced the project’s outcomes. Participant confidentiality will be maintained through data encryption, de-identification, and secure storage. Results: Expected Results: The study anticipates identifying key barriers and facilitators in the SYNC system’s development, including technical, organisational, and collaboration-related challenges. The findings are expected to provide a detailed account of the challenges encountered, such as delays, security concerns, and coordination issues, an insight into how these challenges were mitigated and lessons learned and recommendations for improving digital health technology development, including best practices for co-design, technical integration, and stakeholder engagement. Conclusions: Conclusion: This case study will provide valuable insights into the complexities of developing digital health technologies, particularly in collaborative, multi-stakeholder environments. Documenting the challenges encountered in the SYNC system’s development will contribute to best practices in digital health innovation.