Table Of Contents

The Bottleneck

Step 1: The Memory Slab

Step 2: JSExport Bridge

Step 3: DOM Mutation

The Performance Payoff

Compile-time Generation with Roslyn

Try it yourself!

The Bottleneck: When WebAssembly UI gets sluggish

If you've ever built a heavy data grid, a real-time telemetry dashboard, or a line-of-business spreadsheet application in Blazor WebAssembly, you've likely hit the rendering wall.

Blazor WASM is incredibly productive, but when thousands of cells change multiple times a second:

Every property change triggers an event.

Every event triggers standard Blazor component cycle overhead ( StateHasChanged ).

The Virtual DOM (VDOM) diffs the old rendering tree with the new one.

JS-Interop serializes the diffs and updates the browser DOM.

Under high frequency (like 100+ updates per second on 5,000+ fields), this pipeline stutters.…