Hark

Member of Technical Staff, Distributed Training Performance

Hark
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2 days ago
San Jose, CA, USASenior
H1B sponsor

Base Salary

$180k - $450k/yr

Responsibilities

  • Own MFU and step-time targets for large-scale pretraining runs across dense and mixture-of-experts models.
  • Develop or integrate fused and custom kernels for attention, normalization, and mixture-of-experts routing using CUDA, Triton, and CUTLASS.
  • Optimize communication overlap, pipeline execution, activation recomputation, memory use, sharding, and data, tensor, pipeline, sequence, context, and expert parallelism.
  • Profile GPU kernels, collective communication, data loading, and mixed-precision training to identify throughput and numerical-stability bottlenecks.
  • Develop reusable training components for new architectures and multimodal speech, vision, and text encoders.
  • Investigate performance regressions and training failures involving communication, numerical changes, hardware faults, and straggling nodes.
  • Collaborate with architecture researchers and compute infrastructure engineers to align model designs, training software, and cluster capabilities.
  • Improve checkpointing, restart time, failure detection, and observability, and participate in on-call support during large runs.

Requirements

  • Experience developing distributed training systems and working with Megatron-LM, NeMo, or a comparable framework and its parallelism strategies.
  • Strong understanding of data, tensor, pipeline, sequence, context, and expert parallelism, including communication patterns, memory tradeoffs, and failure modes.
  • Experience using GPU profilers to analyze kernel execution, memory bandwidth, communication overhead, and data-loading stalls.
  • Working knowledge of mixed-precision training, including BF16 and FP8, and methods for diagnosing numerical instability.
  • Strong Python and C++/CUDA engineering skills, with experience building reliable tools for researchers.
  • Experience developing CUDA or Triton kernels, or using CUTLASS, for attention, normalization, or mixture-of-experts models.
  • Demonstrated record of measurably improving MFU or throughput on large-scale training jobs.
  • Bonus qualifications include large-scale mixture-of-experts training, NCCL or topology-aware scheduling, fault-tolerant or elastic training, multimodal encoder workload balancing, Slurm, Kubernetes, and fleet-scale GPU health monitoring.

Benefits

  • Full-time position.
Hark

About Hark

1-10 employees
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