We sped up Notion in the browser with WASM SQLite

The article discusses how Notion improved its performance in web browsers by implementing WebAssembly (WASM) SQLite. By using the OPFS and Web Workers technologies, Notion was able to enhance page navigation times by 20 percent in modern browsers. The architecture involved a SharedWorker-powered approach to manage SQLite queries from multiple tabs efficiently. Initially, simpler approaches faced challenges like cross-origin isolation requirements and corruption issues due to concurrency problems. Notion overcame these obstacles by developing a SharedWorker architecture that allowed for efficient SQLite usage across tabs. Despite initial regressions like slower initial page loads and certain devices not benefiting from caching, Notion optimized the implementation to ensure a seamless user experience. By choosing the OPFS SyncAccessHandle Pool VFS variant, Notion avoided the need for cross-origin isolation, enabling the feature to be rolled out to a wider range of browsers. Overall, the article highlights the technical intricacies and solutions involved in speeding up Notion in web browsers using WASM SQLite.