Software Engineer, Compute and Isolation
About The Position
Baseten is hiring a Software Engineer for its Agent Infra team, which builds the microVM infrastructure underlying Baseten Sandboxes. Each agent sandbox runs in its own microVM, where agents can write and execute code, call tools, and preserve state across long tasks. The role focuses on making microVMs start, stop, snapshot, fork, and resume quickly while maintaining tenant isolation. The team operates bare-metal servers and custom Linux kernels, building cloud infrastructure for multi-tenant workloads. You will own sandbox lifecycle and performance across host and guest systems, including CPU and memory configuration, identity, storage attachments, and virtual network devices. The work spans userspace, the kernel, and hardware, and includes contributing to architecture and open-source projects. The team is small, with broad individual ownership and a focus on shipping in weeks and months.
Requirements
- Hands-on experience with KVM and at least one of Firecracker, Cloud Hypervisor, or QEMU.
- Deep understanding of Linux internals, including namespaces, cgroups, memory management, and the boot path.
- Experience building cloud infrastructure as the provider, including multi-tenant compute that customers run on, rather than 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++ is also welcome.
- Experience debugging performance and correctness problems across userspace and kernel boundaries.
- Ability to move fast and own a problem end to end on a small team.
Nice To Haves
- Contributions to KVM, Firecracker, Cloud Hypervisor, QEMU, rust-vmm, or the Linux kernel.
- Experience with Xen.
- Working knowledge of container runtimes and sandboxing, such as containerd, runc, gVisor, or 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.
- Experience building a sandbox, serverless, or function runtime product.
- Familiarity with Linux performance tooling such as eBPF, perf, and ftrace.
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 operated.
- 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, including its identity, storage attachments, and virtual devices connecting 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 to the open-source projects the team builds on.
Benefits
- Competitive compensation, including meaningful equity.
- For U.S. employees: 100% coverage of medical, dental, and vision insurance for employees and dependents.
- Flexible PTO policy, including company-wide Winter Break, when offices are closed from Christmas Eve to New Year's Day.
- Paid parental leave.
- Fertility and family-building stipend through Carrot.
- For U.S. employees: company-facilitated 401(k).
- Exposure to a variety of ML startups, offering learning and networking opportunities.
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What This Job Offers
Job Type
Full-time
Career Level
Mid Level
Education Level
No Education Listed
