Runtime Engineer

What MatX is BuildingMatX 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 HereBuild the host-side interface library — device memory management, DMA, streams and events, sync primitives — that every compiler-emitted program runs on top ofOwn and extend the executable format: the compilerruntime contract, its versioning, the weight and quantization layouts that let compiler and runtime evolve independentlyDesign 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 deviceBuild Python bindings via PyO3, with a C-ABI shim as the alternative integration path for downstream consumersBuild the LLM inference serving stack — paged KV cache, continuous batching, request scheduling, token streaming — and the cluster orchestration primitives underneath itBring up interconnect topology from the host and own the failure-detection and clean-teardown path for stop-restructure-resume recovery across racksDesign 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 throughputWho You AreStrong experience in a systems programming language — Rust, C, C++, or Go — including memory management, allocator design, and FFI/ABI workHave 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'sHands-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 launchML-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 HaveLLM 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 workCustom allocator design (slab, paged, arena) or other low-level memory workML 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-upCompensationThe 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 - $120,000 - $250,000 + equityMid Career - $175,000 - $362,500 + equitySenior Career - $250,000 - $475,000 + equityWhat We OfferA Stake in our success A flexible cash equity compensation mix that fits your needsHealth & Wellness Company subsidized Health, Dental, Vision, and Life insurance; Pre-tax Health Savings Accounts with generous company contribution (even if you don’t)Time To Recharge 4 weeks paid time off (accrued), 12 company holidays, and 3 weeks remote/flexible work per yearSupport to Parents Up to 12 weeks of paid parental leave, regardless of your path to parenthoodLearning & Development $1,500 yearly towards your professional development e.g. conferences, courses, and other learning opportunitiesTeam Connection Team Lunches, quarterly off-sites, and regular town hallsFinancial Wellbeing. 401K and/or Roth IRA, with 5% company contribution, even if you don’t!Flexible Spending Accounts Pre-tax spend accounts for medical, dental/vision, dependent care, parking, and transit expensesCommute On Us For those commuting up to 1 hour, put your rideshare cost on our company card and reclaim the drive-time to get work done!MatX E[x]tras $50 per month to use on the perks you care about most Remote Perks We work remotely Monday & Friday, supported by home-tech setup, and remote wifi expense reimbursementAs part of our dedication to the diversity of our team and our focus on creating an inviting and inclusive work experience, MatX is committed to a policy of Equal Employment Opportunity and will not discriminate against an applicant or employee on the basis of race, color, religion, creed, national origin or ancestry, sex, gender, gender identity, gender expression, sexual orientation, age, physical or mental disability, medical condition, marital/domestic partner status, military and veteran status, genetic information or any other legally recognized protected basis under federal, state or local laws, regulations or ordinances.This position requires access to information that is subject to U.S. export controls. This offer of employment is contingent upon the applicants capacity to perform job functions in compliance with U.S. export control laws without obtaining a license from U.S. export control authorities.MatX does not accept unsolicited resumes from individual recruiters or third-party recruiting agencies in response to job postings. No fee will be paid to third parties who submit unsolicited candidates directly to our hiring managers or People team and any resumes submitted are deemed to be the property of MatX.