Vibe Coding
A teardown of the VMs behind cloud coding agents: Claude Code boots a custom Firecracker kernel with a Rust PID 1 in 430ms
Rohan Adwankar disassembled the sandboxes behind two hosted agents. Claude Code runs Firecracker KVM guests on a custom kernel (6.18.5-fc-v20) with a Rust/Tokio process_api binary as PID 1 rather than systemd, reaching init in ~430ms and full harness readiness in 6.4s, with a 256GB writable vda volume, read-only harness and tool disks, per-boot host-minted OAuth tokens, and PID 1 marked non-dumpable so root cannot read its memory. Instinct instead rents E2B sandboxes on stock Ubuntu 22.04.5, cold-booting to an XFCE desktop in ~1.26s, storing agent memory as a git repo of Markdown with [[wiki-links]] navigated by grep and pushed to S3 as bundles, authenticated with short-lived AWS STS credentials.
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