Building Bivack: A Cloud Dev Sandbox for Coding Agents on AWS Lambda MicroVMs

Developer Gunnar Grosch has introduced Bivack, an open-source project designed to provide persistent, cloud-based development environments for AI coding agents. Moving away from local laptop-bound setups, Bivack utilizes AWS Lambda MicroVMs to create isolated, disposable sandboxes that are accessible via a browser-based terminal or VS Code workbench. Each user is assigned a dedicated MicroVM with a persistent home directory backed by Amazon S3 Files, allowing developers to switch between devices—such as a phone or laptop—without losing their session, agent state, or file context. The architecture addresses the limitations of local environments by ensuring that long-running tasks continue even when the user is offline. By leveraging Firecracker snapshots and S3-based storage, Bivack offers a scalable, cost-effective solution for managing agentic workflows, ensuring that development environments remain consistent, secure, and available from anywhere without requiring local installation or persistent hardware.