Senior Firmware Engineer, Edge AI / NPU Runtime

Job description

About Tacit We are an early-stage, deep tech startup based in San Francisco, developing innovative hardware that rethinks human-computer interaction. We are backed by General Catalyst, Khosla Ventures, and Greylock Partners, with a founding team from Stanford, BrainGate, Oculus, and Tesla. While we can’t reveal too much just yet, our team is tackling cutting-edge engineering challenges to bring revolutionary products to life. ABOUT THE ROLE We’re looking for a Senior Firmware Engineer, Edge AI / NPU Runtime to help architect, optimize, and ship next-generation neurotech hardware with production-grade on-device intelligence. You will own critical parts of the embedded AI stack, from realtime sensor acquisition through preprocessing, NPU/DSP-accelerated inference, postprocessing, telemetry, and product deployment. This is a hands-on role for someone who wants to work close to the hardware while shaping the intelligence users experience in the product. You’ll help define how models run on-device, how sensor data moves through the system, and how we meet tight latency, reliability, and power budgets in real-world use. WHAT YOU'LL DO - Edge AI & NPU Inference - Own deployment of ML models onto embedded targets using NPUs, DSPs, MCUs, or other hardware accelerators. - Integrate embedded inference runtimes, vendor NPU/DSP SDKs, and model deployment workflows into production firmware. - Optimize inference latency, memory footprint, throughput, power consumption, and accelerator utilization on production hardware. - Partner with ML teams on quantization, operator support, model architecture tradeoffs, calibration datasets, and accuracy/performance regressions. - Realtime Sensor-to-Inference Systems - Build realtime sensor-to-inference pipelines, including acquisition, timestamping, synchronization, preprocessing, feature extraction, model execution, and postprocessing. - Design low-latency data movement using DMA, interrupts, ring buffers, deterministic scheduling, and efficient memory layouts. - Support streaming inference patterns such as sliding windows, temporal models, event-driven execution, and continuous sensor processing. - Maintain inference quality and timing guarantees under real-world conditions such as sensor noise, clock drift, dropped samples, variable system load, and power-state transitions. - Power-Optimized Embedded Firmware - Optimize end-to-end energy per inference across sensing, preprocessing, model execution, postprocessing, and idle time. - Use low-power firmware techniques such as sleep states, duty cycling, subsystem power gating, clock scaling, batching/windowing, and dynamic power management. - Profile and improve power consumption across sensors, CPU, NPU/DSP, memory, and supporting firmware infrastructure. - Product Quality & Debugging - Bring up and debug firmware across sensors, accelerators, power systems, embedded compute, and production hardware. - Use lab tools, traces, logs, telemetry, and instrumentation to root-cause complex embedded system issues. - Translate product and customer experience goals into concrete latency, reliability, responsiveness, and power targets. - Build diagnostics, validation hooks, and performance benchmarks to ensure reliable real-world edge inference behavior. REQUIREMENTS - 5+ years of experience in embedded firmware, embedded systems, or edge ML systems. - Strong C/C++/Rust experience on resource-constrained embedded platforms. - Experience with RTOS-based systems such as FreeRTOS, Zephyr, ThreadX, or similar. - Experience deploying or optimizing ML inference on embedded targets, NPUs, DSPs, MCUs, or edge SoCs. - Strong understanding of realtime embedded systems, including DMA, interrupts, concurrency, memory management, and low-latency data movement. - Experience optimizing embedded systems for latency, memory footprint, throughput, and power consumption. - Hands-on debugging and bring-up experience across embedded hardware and firmware systems, with strong cross-functional communication across firmware, ML, electrical, software, and product teams. STRONG CANDIDATES MAY HAVE - Experience with embedded inference runtimes, deployment toolchains, or edge AI SoCs/accelerators such as TensorFlow Lite Micro, ONNX Runtime, CMSIS-NN, Qualcomm QNN/SNPE, ARM Ethos-U/Vela, TVM, ExecuTorch, Qualcomm, ARM, Cadence/Tensilica, Syntiant, Ambiq, Nordic, NXP, ST, Hailo, Google Edge TPU, or similar. - Experience with quantized inference, fixed-point math, SIMD/DSP optimization, accelerator programming, or model conversion workflows. - Experience with streaming or time-series ML workloads such as biosignals, sensor fusion, audio, gesture recognition, keyword spotting, or other realtime inference systems. - Experience shipping battery-powered consumer electronics, wearable, neurotech, AR/VR, robotics, camera, IoT, or other embedded AI products. COMPENSATION RANGE $150,000 - $200,000/year BENEFITS - Competitive equity package - Comprehensive medical, dental, and vision insurance - Company size: 20-30 people - Unlimited PTO - Visa sponsorship - 4% 401k matching