This study examines how online food delivery platforms can be designed to enhance Digital User Fulfilment (DUF) for frequent users in high frequency digital service contexts. Building from Self-Determination Theory and supported by post-use evaluative and value-alignment perspectives, the study conceptualizes fulfilment as a system-level outcome enabled by three platform provisions: Autonomy-Facilitating Design (AFD), Efficacy-Supporting Design (ESD), and Sustainability-Aligned Practices (SAP). Survey data were collected from high-frequency users of online food delivery platforms, each having placed at least six orders in the previous three months, ensuring repeated interaction with the system. The proposed model was tested using PLS-SEM (estimated using SmartPLS4). The results indicate that autonomy-facilitating and efficacy-supporting design features have significant direct effects on digital user fulfilment, while sustainability-aligned practices emerge as the strongest driver and a key mediator. These findings suggest that users meaningfully relate to sustainability-oriented platform practices, and that this relationship can be strategically leveraged by platform engineers to support stable interaction and enhance system productivity. The study contributes to engineering and operations management literature by demonstrating that sustainability-aligned design is not merely an ethical consideration but a productivity-enhancing lever in high-frequency digital service systems. Practically, it offers actionable guidance to achieve productive digital engagement.

Keywords

Digital User Fulfilment, Human-Centric Platform Design, Sustainability-Aligned Practices, Productivity-Oriented Digital Engagement, Online Food Delivery Platforms