Topcoat enables Rust to render server-side web apps

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.