Högskolan i Skövde

The thesis uses a quantitative experimental research method to find differences in performance, user experience, and developer experience between the front-end frameworks Blazor and React. The thesis aims to provide a comprehensive comparison between Blazor and React, both when using Server -Side (Blazor Server and React Server-Side Rendering) and Client-Side (Blazor WebAssembly and React Client-Side Rendering) methods. The experiment conducted in the thesis consisted of the development of four applications which were identical in all ways but framework and rendering methods ; Blazor WebAssembly, Blazor Server, React Client-Side, and React Server-Side. These applications were designed based on a legacy system currently in use by Volvo Digital Technology & Operations. The experiment consisted of running four different performance tests on each of the applications: Playwright with initial load, Playwright without initial load, Lighthouse, and Google DevTools performance. During the performance tests, the only outlier was Blazor WebAssembly. The performance test results were then used alongside multiple user experience guidelines to establish if the frameworks and rendering methods had an impact on user experience. Here Blazor WebAssembly was again the only outlier. The research also included gathering data from three developer communities to compare the available community support for React, Blazor, JavaScript, and .NET by visiting the communities’ tags and tallying the total posts. This was made to give an insight into the developer's experience with the two frameworks. JavaScript and React together represented 89.95% of the total posts counted. Aside from the experiment, the thesis also touches on the subject of modernization and reasons for an organization to move away from legacy systems, and concluded that legacy systems are expensive, limit organizational flexibility, and finding experts of aged architecture is harder as modern frameworks rise in popularity.