The shift toward Deno’s permission-based runtime

Ryan Dahl’s vision for security

Ryan Dahl and Bert Belder built Deno to fix architectural mistakes in Node.js, specifically regarding unrestricted filesystem and network access. Dahl, who introduced Node.js in 2009 and worked at Google Brain, seeks to tame the complexity of distributed web infrastructure. Deno is a runtime for JavaScript and TypeScript based on the Rust programming language and Google’s V8 engine. This runtime requires explicit permissions, meaning a script needs the --allow-net flag to access the network. This model prevents malicious dependencies from accessing local files or environment variables without user consent. I find these strict boundaries necessary for modern development. Deno 2 also simplifies TypeScript use by removing the need for complex transpilation. Deno 2.0 also improved HTTP server performance by up to 35%. Deno includes a formatter, a linter, a test runner, and a debugger. Deno’s design is to provide a productive and secure scripting environment for managing servers and performing scientific computations. Deno has over 100,000 GitHub stars.

Moving workloads to the edge

Deno Deploy reached general availability in February 2026 and operates in 33 regions. The company reported 400,000 monthly active users in August 2026. Deno switched from AWS and GCP to Vultr to save $10,000 every month. By switching from AWS and GCP to Vultr, Deno unlocked significant improvements in cost savings and performance, which allowed the company to scale its global edge footprint without ballooning its monthly infrastructure budget. You already know that Bun prioritizes speed, so consider the performance trade-offs. Bun often outperforms Deno in raw throughput, hitting 52,000 requests per second compared to Deno’s 29,000 requests per second. I find the speed difference between these two runtimes unacceptable for high-performance microservices. Bun is a toolkit that uses the JavaScriptCore engine from Apple and the Zig language to achieve its speed. Will the performance gap between Bun and Deno eventually narrow? Deno 2 compensates for this lower speed by offering improved Node and npm compatibility through npm: specifiers. Deno 2 also understands package.json and node_modules, which eases the transition for teams leaving Node.js. Deno’s microVM-based sandboxing further supports the execution of untrusted code. Deno Deploy provides a free tier along with paid plans that scale with usage.

Deno runtime specifications

Deno manages its growth with 17 employees and plans to hire 10 more by next year. The company raised a total of $30.9 million, including a $21 million Series A round led by Sequoia. Deno also received a $5 million seed round in March 2021. Other backers include the Mozilla Corporation, Four Rivers Ventures, Rauch Capital, Long Journey Ventures, and Shasta Ventures.

Deno integrates the JSR package registry to allow authors to publish TypeScript source with Sigstore provenance. This registry works across Node, Deno, and Bun. Deno also includes built-in tools like deno fmt and deno lint to reduce reliance on external packages. Authors using the JSR registry receive automatically generated documentation. Dahl’s work on Dactyl uses WebAssembly-based SwiftUI to simulate applications inside the browser. This project enables interactive previews and browser-mediated authentication. His Claw Patrol project is an open-source, protocol-aware agent firewall. This firewall inspects outbound traffic and evaluates centrally managed policies to block dangerous database operations. Claw Patrol can also request human approval for sensitive tasks. Deno’s architecture as an isolate cloud supports the next wave of web development that relies on edge optimizations. Deno also collaborated with Slack to develop the company’s next-generation development platform. Deno Deploy provides framework-aware builds and deployment previews. The platform also provides automatic logs and traces for application teams.