Note: The job is a remote job and is open to candidates in USA. MatX is building custom silicon for large-language-model inference and training, with hardware and software co-design across the stack. The Runtime Engineer builds and owns the host-side runtime, compiler interfaces, inference serving stack, and related performance, debugging, and recovery capabilities.
Responsibilities
- Build the host-side interface library — device memory management, DMA, streams and events, sync primitives — that every compiler-emitted program runs on top of
- Own and extend the executable format: the compiler→runtime contract, its versioning, the weight and quantization layouts that let compiler and runtime evolve independently
- Design the custom-kernel ABI — calling convention, sync semantics, lifecycle — and the host-side marshaling layer (DLPack, the buffer protocol, numpy) that gets Python tensors to the device
- Build Python bindings via PyO3, with a C-ABI shim as the alternative integration path for downstream consumers
- Build the LLM inference serving stack — paged KV cache, continuous batching, request scheduling, token streaming — and the cluster orchestration primitives underneath it
- Bring up interconnect topology from the host and own the failure-detection and clean-teardown path for stop-restructure-resume recovery across racks
- Design what the chip exposes to host-side profilers and debuggers — perf counters, traces, and the Python surfaces ML engineers actually use — and hit measurable performance targets on runtime overhead and serving throughput
Skills
- Strong experience in a systems programming language — Rust, C, C++, or Go — including memory management, allocator design, and FFI/ABI work
- Have built Python interop layers in production (PyO3, ctypes, pybind11, or equivalent C-ABI bridging)
- Have designed and maintained API or ABI contracts between teams — versioning, evolution, breaking-change discipline — not just consumed someone else's
- Hands-on with at least one accelerator programming model (CUDA, ROCm, oneAPI Level Zero, TPU, or comparable) — enough to reason about device memory, async execution, and kernel launch
- ML-systems literate — comfortable with the training and inference loop, what collectives do, what a tensor layout is. Research depth not required
- LLM inference internals — vLLM, TensorRT-LLM, or SGLang (paged attention, scheduler design)
- Rust at depth, including proc macros, unsafe with soundness reasoning, and complex lifetime/trait work
- Custom allocator design (slab, paged, arena) or other low-level memory work
- ML framework integration experience (PyTorch custom backends, JAX/XLA, ONNX runtime)
- Profiler or tracing infrastructure work (perfetto, Nsight, or a custom stack)
- Driver-adjacent or kernel-bypass work, or prior new-silicon bring-up
Benefits
- 4 weeks PTO (accrued) + 12 company Holidays + up to 3 weeks remote work
- Company-subsidized Medical (Kaiser or Anthem) for employees & dependents
- Guardian Dental and Vision insurances for employee & dependents
- Life insurance (employee only)
- HSA and FSA offerings via Lively
- Choose from Roth or pre-tax 401K (or both) with a 5% company contribution (even if you don't contribute)
- 100% company-paid life insurance (up to $300K)
- Long-term disability and travel insurance
- $1500 per year Professional Development Budget
- MatX provides onsite team lunch & dinner Monday - Friday, with your choice of ordering via WeBox, Specialty’s or via our reimbursement system
- We pay 100% for your daily commute. Commute via our company rideshare account, reimburse public transportation, or get a Fasttrak card (or all three)
- $50/mo to use on the perk you value most
- $35/mo for cellular and $40/mo for wifi
- Use our Amazon business account for up to $1000 in office setup purchases
- 100% paid mental health benefit via SpringHealth and Guardian EAP
- Up to 12 weeks paid parental leave regardless of path to parenthood
- 10 weeks pregnancy disability leave
- Flexible return-to-work hours
- A $6K Family Fund to cover fertility, surrogacy, adoption, menopausal health, preservation, family counseling and more
Company Overview