The digital transformation of public services has emerged as a cornerstone of administrative modernization, profoundly redefining interactions between public institutions and private sector actors. This study examines the determinants of perceived performance of public service digital platforms from the perspective of Moroccan private professionals. Anchored in an integrated conceptual framework that combines the IS Success Model with the Technology Acceptance Model (TAM), this research adopts a qualitative methodology based on twelve semi-structured interviews. The thematic analysis reveals that perceived performance extends beyond technical functionalities to encompass system quality, information quality, service quality, and perceived usefulness. While users commend the operational efficiency and time savings facilitated by these platforms, they also highlight persistent challenges, notably insufficient user-centric design, limited interoperability, and inadequate support services. This study contributes to the broader e-government literature by shedding light on the underexplored experiences of private sector users in emerging economies and provides actionable insights for policymakers seeking to improve the effectiveness, transparency, and trustworthiness of digital public services.