The rapid evolution of enterprise software development over the past two decades has been characterized by a persistent tension between platform specificity and cross-platform abstraction. This tension has shaped the emergence, maturation, and convergence of web frameworks, mobile development paradigms, and backend architectures that collectively underpin modern digital ecosystems. Against this backdrop, the transformation of ASP.NET into ASP.NET Core represents not merely a technological upgrade, but a paradigmatic shift in how enterprise-grade, cross-platform, cloud-native applications are conceptualized, engineered, and maintained. This article develops an extensive and critical examination of the architectural evolution of ASP.NET Core in relation to broader cross-platform development strategies, situating this evolution within historical, theoretical, and empirical research traditions drawn from software engineering, model-driven development, and mobile application frameworks.

Drawing strictly on the provided scholarly corpus, the article synthesizes insights from early cross-platform research, object-oriented design theory, and contemporary empirical evaluations of performance overhead in hybrid and native frameworks. The analysis positions ASP.NET Core as a unifying infrastructural layer that responds to long-standing challenges in portability, maintainability, performance optimization, and organizational scalability. Particular attention is devoted to tooling ecosystems, architectural modularization, dependency injection, runtime unification, and deployment strategies that align with cloud-based and microservice-oriented practices. By critically engaging with comparative studies of cross-platform mobile frameworks such as PhoneGap, Flutter, and Titanium, the article elucidates how backend evolution and frontend abstraction are increasingly co-dependent phenomena.

Methodologically, the study adopts a qualitative, literature-grounded analytical approach, reconstructing conceptual linkages across diverse research domains while maintaining rigor in citation and interpretive transparency. The results demonstrate that ASP.NET Core’s design philosophy reflects a broader epistemic shift in software engineering away from monolithic, platform-bound systems toward flexible, runtime-agnostic architectures that can serve heterogeneous client environments. The discussion advances a nuanced theoretical interpretation of these findings, addressing counter-arguments related to abstraction overhead, ecosystem fragmentation, and long-term sustainability. The article concludes by articulating implications for enterprise architects, researchers, and policymakers, and by outlining future research trajectories that bridge backend evolution with cross-platform application performance, governance, and digital health use cases.