Simon Willison’s Weblog

22nd May 2019 - Link Blog

WebAssembly at eBay: A Real-World Use Case (via) eBay used WebAssembly to run a C++ barcode reading library inside a web worker, passing images from the camera in order to provide a barcode scanning interface as part of their mobile web “add listing” page (a feature that had already proved successful in their native mobile apps). This is a great write-up, with lots of detail about how they compiled the library. They ended up running three barcode solutions in parallel web workers—two using WebAssembly, one in pure JavaScript—because their testing showed that racing between three implementations greatly increased the chance of a match due to how the different libraries handled poor quality or out-of-focus images.