Drawing on service-dominant (SD) logic, which conceptualizes value as emerging through resource integration and use rather than direct technological outputs, the study examines how technology-mediated knowledge-sharing platforms (TMKSP) influence employee and employee-perceived customer experience using the DART (dialogue, access, risk assessment, transparency) framework of value co-creation. Employing a mixed-method approach, a pre-hoc qualitative study (Study A) identified key TMKSP features relevant to value co-creation, which informed the development of a DART-based survey for the quantitative phase (Study B). Data from retail employees were analyzed using PLS-SEM with two-tailed bias-correct bootstrapping. The findings show that TMKSP significantly improves employee experience via platform access and reduced perceived risk, while enhancing employee-perceived customer experience through employee-customer dialogue and platform transparency. Mediation analysis confirms the explanatory role of DART-based constructs in linking TMKSP with experience outcomes, although the mediating role of perceived platform risk was not supported. The study contributes theoretically by operationalizing SD logic within an internal service ecosystem and demonstrating how value-in-use is shared through employee-perceived co-creation conditions rather than through direct technological effects. It offers practical guidance for managers aiming to design employee and customer-centric knowledge-sharing ecosystems.