Popular for other uses, Rust isn’t typically deployed for web development. That could change, however. With AI here to do the heavy lifting, coders may want to consider the programming language, given its runtime performance and safety guarantees, suggested Carl Lerche , an Amazon Web Services principal engineer, speaking at ScyllaDB’s 2026 P99 virtual conference last week. Lerche was there to demonstrate his latest project, Topcoat , a framework for running web applications written in Rust. Lerche is perhaps best known for creating Tokio , which is the most popular asynchronous Rust runtime in that ecosystem. “Three years ago, had [I] gone out and said that Rust could be the best language for building web apps, you probably would have called me crazy,” he told the virtual audience. Web developers gravitate towards the languages they find most familiar. These days, that means JavaScript, or possibly Ruby. A number of web frameworks already use Rust. Both Leptos and Dioxus compile Rust into WebAssembly, which most browsers run. This approach is great for heavy computational jobs, though the upfront loading time can be a real drag. Topcoat compiles your Rust code into more web-friendly JavaScript. For Lerche, JavaScript remains the best way to interact with the browser’s Document Object Model (DOM). “Generally, the approach taken by any Rust framework can be traced back to another ecosystem, usually a very popular one. You can’t really point to a single existing framework as [Topcoat’s] main source of inspiration,” noted frontend developer Ken Kohlman, in a summary video on his “Code to the Moon” YouTube channel. Walk on the server side
Lerche admitted that Topcoat isn’t for building complex applications, on the scale of, say, Figma, but it can easily be used for the run-of-the-mill, browser-based, database-driven applications, which is to say 90 percent of the web today. Unlike most present-day JavaScript frameworks , Topcoat eschews the current definition of being reactive, where the program logic is dumped onto the browser when the session begins. Instead, most of the logic executes on the server, with only the results delivered to the browser (Developers can still write client-side logic using a subset of Rust, which Topcoat automatically compiles into JavaScript for the browser)…