Member of Technical Staff, Hardware, Kernel Engineer (Custom Silicon)

River AI is on a mission to create personal AI owned and shaped by individuals, focusing on developing custom hardware and deep learning research. They are seeking a Kernel Engineer to design and implement optimized kernel generators for their high-performance custom silicon, collaborating closely with various teams to enhance compute efficiency.

Responsibilities:

• Kernel Generator Development: Design and build C++ code-generation frameworks and meta-programming toolchains that automatically emit optimized custom ISA assembly code
• Low-Level Compute Optimization: Author and optimize core deep learning primitives (GEMM/MatMul, Attention mechanisms, Convolutions, and element-wise layers) directly targeted at our custom hardware
• Microarchitectural Tuning: Hand-craft and automate instruction scheduling, register allocation, and software pipelining to maximize ALU utilization and hide execution latency on our silicon
• Memory Hierarchy Management: Design sophisticated tiling, double-buffering, and data-movement strategies to optimize on-chip SRAM utilization and minimize memory bandwidth bottlenecks
• HW/SW Co-Design: Partner with the RTL and architecture teams to evaluate hardware simulations, provide feedback on the ISA, and influence the design of future compute units based on kernel execution profiles
• Performance Profiling & Validation: Benchmark generated assembly against hardware simulators and silicon, utilizing hardware performance counters to eliminate performance gaps and ensure mathematical correctness