Runtime Engineer
- Market p25–p75
- $161k–$239k
- MatX p25–p75
- $218kn=22
- H-1B median · Software engineering
- $216k
- Opened · 30d
- +1
- Closed · 30d
- −0
- Opened · 7d
- +2,3586% of open
- All software engineering
- 75,186open
What MatX is Building
MatX is building custom silicon for large-language-model inference and training, with HW/SW co-design across ISA, RTL, simulator, compiler, and kernels so each layer benefits from the others. The runtime owns the host-side stack and the contracts that bind those teams together.
What You'll Do Here
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
Who You Are
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.
Bonus Points If You Have
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
Compensation
The US base salary for this full-time position is determined based on a variety of factors including role, experience, location, job-related skills, and relevant education and training. Career length is only a guideline for compensation.
Early Career - $160,000 - $250,000 + equity
Mid Career - $175,000 - $362,500 + equity
Senior Career - $250,000 - $475,000 + equity
What We Offer
Time off: 4 weeks PTO (accrued) + 12 company Holidays + up to 3 weeks remote work
Health: Company-subsidized Medical (Kaiser or Anthem) for employees & dependents, Guardian Dental and Vision insurances for employee & dependents, and life insurance (employee only), plus HSA and FSA offerings via Lively.
Financial Security: 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.
Professional Development: $1500 per year Professional Development Budget
Team Meals: MatX provides onsite team lunch & dinner Monday - Friday, with your choice of ordering via WeBox, Specialty’s or via our reimbursement system
Commute on Us: We pay 100% for your daily commute. Commute via our company rideshare account, reimburse public transportation, or get a Fasttrak card (or all three)