<p>Interest in the potential of population-based genomic sequencing is growing. However, integrating a large-scale screening program into an already complex healthcare system is challenging. The implementation of gNBS needs a thorough understanding of the process. The purpose of this study is to investigate how gNBS can be integrated into the Australian health system and delivered at scale. Embedded within the BabyScreen+ study, we utilised a research design informed by process mapping and phenomenology. Fifty-one semi-structured interviews with parents (<i>n</i> = 33), healthcare providers (<i>n</i> = 15), and BabyScreen+ study team members (<i>n</i> = 8) were conducted. Additionally, we analysed the operational team meeting minutes. A baseline process map, developed in consultation with team members, consisted of six stages: 1. Raising awareness of the screening program; 2. Offer; 3. Participant enrolment and consent; 4. Sample collection; 5. Testing; and 6. Result disclosure and management. We recorded changes made over the study period to inform the post-implementation process map. Most changes occurred at stages: 1. Raising awareness, 4. Sample collection and 5. Testing. Lastly, a process map to inform the scale up of screening, was developed. Four key aspects of the gNBS process needing modification are: (1) growing awareness of screening amongst the public and HCPs; (2) building flexibility and accessibility into the consent process; (3) developing automation capabilities and infrastructure for large-scale sequencing and analysis, and (4) dedicated referral processes for infants who receive high-chance results. These findings demonstrate key system-level considerations and provide a foundation for implementing genomic newborn screening at scale within existing healthcare systems.</p>