How Notion Workers run untrusted code at scale with Vercel Sandbox | Customers | Vercel

What this post added

This post details how Notion leverages Vercel Sandbox to run untrusted code for their Workers. Key technical contributions include the use of Firecracker microVMs for strong isolation, a firewall proxy for credential brokering to prevent secret exfiltration, dynamic network policies for runtime control, and filesystem snapshots for efficient state preservation and fast cold starts. The post also highlights the economic benefits of active-CPU billing combined with snapshots for predictable costs at scale.