WebAssembly has long since ceased to be an experiment. Today, major products such as Figma, Google Earth, and AutoCAD Web are using it in production. The ability to execute code at near native speed right in the browser makes it attractive to developers, especially in parts of the application where JavaScript is a bottleneck. However, the path from idea to production using WASM is not always easy – especially when you are building an application in Rust and are going to do without classic tools like Webpack.
It usually starts with a desire to speed up critical parts of the frontend. Rust quickly turns out to be a favorite – it is reliable, performant and compiles well in WebAssembly. The first steps are simple: cargo new, add wasm-bindgen, write a function, compile under wasm32-unknown-unknown, and voila – the module is ready. Then the question arises: how to connect it to the browser? There are several options. You can use wasm-pack and connect the module as an npm-package. You can build it manually and load it via JS. Or you can use a bandler.
And this is where the culinary experiments begin. Webpack – complicated, verbose, requires configs and tambourine, especially if you need to use wasm-bindgen and work with types. Parcel – seems to be easier, but suddenly starts conflicting with certain versions of wasm-bindgen or crashes when exporting structures. Vite – works fast, but not always stable with WASM modules, especially if the project is not trivial. Each of these tools requires a special recipe.
One of the real examples: when trying to use stdweb instead of wasm-bindgen to bypass Parcel limitations, the developer faced the fact that structures cannot be exported stably – they disappear during build, or are called with errors. The solution didn’t come immediately. After dozens of comments in the issue on GitHub and comparing library versions, it turned out that a stable build is possible only with a certain version of wasm-bindgen, a plugin for Parcel, a patch to the config and manually added init code. This is essentially a custom build recipe that is not officially documented.
Once the technical barriers are overcome, optimization begins. WASM modules are fast, but they are called asynchronously, and this imposes limitations on the architecture. You can’t just call a function from Rust like a normal JS function – you have to consider promises, initialization, and errors. In addition, working with strings and memory requires explicit management. For example, you can’t just return a string from Rust – you need to allocate memory, pass a pointer, decode. All these things require understanding of WASM memory model and wasm-bindgen operation.
Nevertheless, the result is worth it. After all the iterations, you get a module that runs faster than similar JS code, consumes less memory, and most importantly, gives the developer confidence in the types and in the absence of runtime errors. This is what makes Rust+WASM a powerful tool in modern frontend.
Today, WebAssembly is not only used for visual applications. It is used for machine learning in the browser, image and audio processing, math simulations, even emulators. And more and more companies are starting to include it in production, despite the complexities of assembly. The main thing is to realize that this path requires patience and experimentation. As in a real kitchen, there is no universal recipe. Only practice, bugs, fixes, more bugs, and, finally, production.
This is how real WASM applications are born. At first everything seems raw and unstable, but gradually the project takes shape. This is the real “WASM Cooking” – with spices from wasm-bindgen, roasting of compilation errors and serving as a stable and fast application running in the browser.
