Firecracker is the open-source Virtual Machine Monitor (VMM) behind platforms like AWS Lambda, Fly.io, and E2B and a core building block in many sandboxed runtimes and microVM-based systems. It combines the speed and efficiency needed for high-density workloads with a stronger isolation boundary than containers alone, making it a compelling foundation for serverless platforms, sandboxed CI runners, agent infrastructure, and other systems that execute untrusted or multi-tenant workloads.

This course teaches Firecracker from the ground up, but always through the lens of building something real with it. You will start by understanding the core virtualization concepts behind Firecracker - what KVM provides, what a VMM does on top, and why Firecracker is designed the way it is - and then progressively assemble more production-like setups. Along the way, you will learn how to boot microVMs manually, control them through the REST API and Go SDK, connect them to the network using both low-level Linux primitives and CNI plugins, communicate with guests over SSH and VSOCK, provision efficient copy-on-write root filesystems, and harden the runtime with the jailer.

By the end of the course, you will have both a solid mental model of how Firecracker works and the practical skills to use it as an infrastructure primitive. Whether you want to build a lightweight VM-based control plane, launch secure per-task sandboxes, or ship infrastructure for autonomous agents, this course will show you how to turn Firecracker from an interesting piece of technology into something you can actually use.