Boost the rendering speed
When Blazor apps must render a large number of items that need to be accessible at any moment, virtualization comes in handy. Make components lightweight in order to keep the UI quick and responsive.
Excessive calls should be avoided. JS interop calls are asynchronous by default. On the Blazor WebAssembly hosting model, you can use synchronous JS interop calls.
Use ahead-of-time (AOT) compilation
AOT-compiled apps are bigger and take longer to download, but they typically deliver superior runtime performance, especially for apps that perform CPU-intensive operations.
Shrink the app download size
Publish Blazor apps in the release configuration with the .NET WebAssembly build tools installed so that runtime relinking is executed automatically, eliminating unnecessary logic. Lazy load assemblies at runtime when the assemblies are needed by a route.