ABOUT BASETEN

Baseten powers mission-critical inference for the world's most dynamic AI companies, like Cursor, Notion, OpenEvidence, Abridge, Clay, Gamma, and Writer. By uniting applied AI research, flexible infrastructure, and seamless developer tooling, we enable companies operating at the frontier of AI to bring cutting-edge models into production. We're growing quickly and recently raised our $1.5B Series F, led by Altimeter Capital, Conviction Partners, and Spark Capital. Join us and help build the platform engineers turn to ship AI products.

THE ROLE

Every agent on Baseten Sandboxes gets its own microVM, where it writes and runs code, calls tools, and keeps state across long tasks. Agents pause and resume constantly, so the machine underneath has to start, stop, snapshot, fork, and resume fast, and keep every tenant isolated while it does. General-purpose virtualization was not built for that workload.

The Agent Infra team builds that layer. Sandboxes run in microVMs with custom Linux kernels on bare-metal servers we operate. You'll own how sandboxes start, stop, snapshot, fork, and resume, and how they perform on each host's CPU and memory, down to the hardware. You'll also own the guest and host side of each sandbox: its identity, how it attaches to different storage classes for performance or capabilities, and the virtual devices that connect it securely to the network. In September 2026, Baseten acquired Blaxel, whose microVM sandboxes are the foundation for Baseten Sandboxes.

We are building a cloud, not just using one. That means designing for many tenants from day one and thinking through what each decision means all the way down to the datacenter. The team is small and ownership is big: we ship in weeks and months, not multi-year programs.

If you've worked deep in KVM and Firecracker, Cloud Hypervisor, or QEMU and want to build the computers AI agents run on, we'd love to talk.

EXAMPLE INITIATIVES

Blaxel is joining Baseten to build the future of agentic infrastructure

Securing the open frontier with NVIDIA OpenShell and Blaxel sandboxes

Baseten Sandboxes documentation

RESPONSIBILITIES

Own the microVM lifecycle for agent sandboxes: start, stop, suspend, resume, snapshot, and fork

Build and tune the custom guest kernels sandboxes run on

Tune host CPU and memory configuration so sandboxes run fast and safely on each type of hardware we operate

Manage host-level resources and sandbox density on each machine

Own startup and resume performance end to end, from VM boot or snapshot restore to the first command

Own the guest and host side of each sandbox: its identity, how it attaches to storage, and the virtual devices that connect it to the network

Design isolation for multi-tenant workloads where the hypervisor is the security boundary

Debug virtualization and isolation issues at scale, from userspace through the kernel to the hardware

Contribute architecture decisions and code back to the open-source projects we build on

REQUIREMENTS

Hands-on experience with KVM, plus Firecracker, Cloud Hypervisor, or QEMU

Deep understanding of Linux internals: namespaces, cgroups, memory management, and the boot path

Experience building cloud infrastructure as the provider (multi-tenant compute that customers run on), not only running workloads on a cloud provider

Experience building multi-tenant infrastructure where isolation is a security boundary

Strong systems programming background in Rust and/or Go; C/C++ also welcome

Experience debugging performance and correctness problems across userspace and kernel boundaries

You move fast and like owning a problem end to end on a small team

NICE TO HAVE

Contributions to KVM, Firecracker, Cloud Hypervisor, QEMU, rust-vmm, or the Linux kernel

Experience with Xen

Working knowledge of container runtimes and sandboxing (containerd, runc, gVisor, Kata Containers)

Experience with VM snapshot and restore, fast VM resume, or building and tuning custom Linux kernels

Experience running virtualization on bare metal and tuning for specific CPU and memory architectures