International community service can connect academic knowledge with the immediate needs of micro, small, and medium enterprises (MSMEs) operating in multicultural urban settings. This article reports a Corporate Social Innovation (CSI) activity conducted by a team from Universitas Pembangunan Nasional “Veteran” Jakarta in collaboration with Universiti Kuala Lumpur at a coffee and snack shop in the lobby of Regalia Residence, Kuala Lumpur, Malaysia. The activity aimed to identify the partner’s operational and marketing challenges, interpret customer-behavior patterns, and formulate feasible customer-oriented recommendations. A participatory business-diagnostic approach was applied through pre-visit desk research, a one-day field visit, direct observation, semi-structured conversations with the owner and staff, informal customer interactions, photographic documentation, and thematic analysis. The diagnostic process identified four interrelated issues: dependence on fluctuating lobby traffic, the need to serve both residents and short-stay visitors, limited differentiation in a competitive food-and-beverage environment, and underutilized customer-retention and digital-promotion opportunities. The service team translated these findings into a practical strategy package comprising time-based menu planning, a simple loyalty mechanism, low-cost digital content, distinctive menu development, and collaboration with residence management. The principal output was a context-specific set of recommendations and a shared understanding of the shop’s market position; however, the short engagement did not permit measurement of post-implementation business outcomes. The activity demonstrates that international community service can create reciprocal learning and actionable value when recommendations are grounded in partner dialogue, local observation, and realistic resource constraints