Deno’s security model and the 2026 runtime competition

Ryan Dahl’s security-first approach

Ryan Dahl created Deno to fix Node.js design flaws like unrestricted filesystem and network access. Deno uses a permission-based model that requires explicit flags like –allow-read or –allow-net. This sandboxed environment prevents malicious packages from accessing sensitive resources without user consent. Deno 2.6 introduced advanced flags like –ignore-read and –ignore-env to fine-tune access control. This security improves safety but can slow rapid development workflows. Deno 2.0 added full package.json compatibility and 95% npm package support, bringing its GitHub stars to 106,000. Deno’s permission model ensures that code cannot escalate its privileges without user consent. The company raised $21 million in a Series A round led by Sequoia to grow Deno Deploy. This Isolate Cloud provides deployment to 33 regions and uses microVM-based sandboxing. Deno is built on Rust and provides a secure environment for executing code via multiple means, including Web Workers. Deno’s permission model allows developers to scope access to specific resources, such as using –allow-read=./data.

Speed and scale differences

Bun and Deno provide faster cold starts than Node.js. Bun achieves 8 to 15 millisecond cold starts, while Deno clocks in at 40 to 60 milliseconds. Bun reaches 260,000 requests per second, while Deno provides 95,000 requests per second and Node.js handles 85,000 requests per second; this makes Bun the leader for high-throughput API services. Bun package installation takes 1 second, whereas Deno takes 38 seconds. Jarred Sumner’s Bun is written in Zig and prioritizes speed, but it lacks a formal LTS policy. I find the speed of Bun impressive, but Deno’s security-first architecture provides more peace of mind for sensitive workloads. Bun 1.3 includes Bun.SQL for unified database access and a built-in Redis client that performs 7.9 times faster than the popular redis package. Bun also reduces JavaScript memory usage by 10 to 30 percent in frameworks like Next.js. Bun uses the JavaScriptCore engine, which allows for 4-tier JIT compilation and better memory efficiency. In I/O-heavy tasks using Express, Node.js handles 14,000 requests per second, whereas Deno handles 29,000 requests per second and Bun handles 52,000 requests per second. Will the performance gap between JavaScriptCore and V8 continue to widen as Bun matures?

Enterprise TypeScript and stability

Enterprise teams often choose Node.js due to its 42.65% adoption and 2.1 million npm packages. Node.js 24, powered by V8 13.6, includes experimental TypeScript support via the –experimental-strip-types flag, though it lacks the full type-checking capabilities found in Deno. Node.js provides predictable 30-month LTS cycles that support large-scale operations. In React Server-Side Rendering tests, Node.js achieves 4,200 operations per second, slightly outperforming Bun at 4,150 operations per second. Deno offers native TypeScript support with no configuration required. You should consider Deno if your team prioritizes security and native type-checking. Deno’s developer experience allows you to run .ts and .tsx files directly without external transpilers or configuration files. Bun also provides a complete toolkit, including a bundler, test runner, and package manager in a single binary. Bun’s package installation is 10 to 25 times faster than npm. Bun’s performance in server response times shows 2 to 4 times improvement in many scenarios. Bun’s package manager executes roughly 165,000 system calls during installation, compared to the nearly 1 million calls performed by npm.