A Comprehensive Evaluation of Cloud Storage Access in Flutter Applications – Direct and API Based

Efficient access to cloud hosted data is an important factor for modern cross-platform applications. Developers working with Flutter must decide between different data retrieval strategies, these include direct database connections and API based intermediaries. However, existing studies often overlook key factors such as PaaS environments, network variability, cross-platform feasibility, and scalability under load. This thesis offers an evaluation of directly connecting to the Azure SQL database through the server, versus a RESTful ASP.NET Core API in a Flutter assessment app. Two application versions were created, one issuing SQL commands directly to the server using an MSSQL library, the other routing requests through an API; both were then subjected to tests simulating diverse network conditions and concurrent user activity. The investigation also examined platform compatibility for direct access and reviewed caching strategies from theliterature to understand their effects on performance and scalability. The findings highlight that secure direct connections from Flutter to the Azure SQL database are unreliable on the Web and Android versions of the app, effectively requiring an API layer to meet security and compatibility demands. However, direct access was successfully established on Windows, where all subsequent performance and scalability tests were conducted. Then a review of the literature examined caching strategies and their impact on performance and scalability. Results revealed that although direct access delivers faster responses in single-user, ideal network scenarios, API mediated interactions maintain consistent performance as user loadgrows and allow for centralized caching to reduce backend load. Both methods slow down inpoor networks, but the additional network hop of the API may contribute to a larger increase in absolute latency. Overall, while direct database connections can offer latency advantages in isolated cases, the API-based approach emerges as the more scalable and practical solution for Flutter apps interfacing with cloud databases. Its strengths in managing concurrent requests, conserving client resources, simplifying maintenance, and ensuring platform-agnostic security support a clearer path for developers aiming to build scalable applications.