Requirements

• Experience working deeply on large-scale training systems, ideally as part of a training group working closely with researchers
• Strong PyTorch fluency, including comfort reading and modifying low-level training code rather than only using high-level APIs
• Experience with distributed training concepts such as FSDP, tensor/model/context/sequence parallelism, activation checkpointing, NCCL, and overlapping compute and communication
• Hands-on experience improving training throughput, memory footprint, or stability in real training runs
• Experience profiling GPU workloads with tools like Nsight Systems, Nsight Compute, torch profiler, trace viewers, or custom telemetry

Nice To Haves

• Have supported or co-owned training for a frontier foundation model that shipped or reached a major release
• Have written or substantially improved forward/backward GPU kernels, or have shown you can make progress on kernel-level work with strong measurement and validation discipline
• Have worked on attention performance, variable sequence length training, non-standard attention patterns
• Have experience on Hopper or Blackwell-class GPUs

What You'll Be Doing

• Improve the performance, reliability, and numerical stability of production training runs for large multimodal generative models
• Profile full training steps across model code, attention, kernels, data loading, encoders, communication, optimizer steps, checkpointing, and memory pressure
• Implement and validate GPU-level optimizations: fused kernels, attention paths, low-precision matmuls, quantization kernels, CUDA/Triton/CuTe/CUTLASS experiments, and no-compile alternatives where they make sense
• Push lower-precision training forward, including FP8 / MXFP8 / FP4-style paths, weight and activation quantization, accumulation choices, convergence risk, and quality tradeoffs against baseline training runs

Perks and Benefits

• We’re a distributed team with real offices that people actually use
• Join us in Freiburg or SF at least 2 days a week or work remotely with a monthly in-person week to stay connected
• Reasonable travel costs covered for in-person meetings
• Obsessed, Low Ego, Bold, Kind values