Senior Research Engineer, Model Training / Pretraining

Senior Research Engineer Seattle, Washington | Hybrid The position is a Senior Research Engineer on the model scaling team, reporting to a Director of AI Research. The work covers model training and the supporting infrastructure. Training runs use approximately 600 B300 and 1,000 H100 GPUs. Responsibilities Build and maintain the training stack for distributed model training across GPU clusters. Run scaling experiments covering model architecture, data, and optimisation. Work in one specialist area: GPU kernel development (CUDA), Mixture-of-Experts architectures, or reinforcement-learning post-training (GRPO, PPO, RLVR). Release models, code, and associated research publicly. Requirements 6+ years of software engineering experience. 4+ years of machine-learning infrastructure experience. Python and PyTorch. Experience training models from scratch (pretraining). Experience limited to retrieval-augmented generation or application-level fine-tuning does not meet this requirement. Depth in at least one of: CUDA kernels, Mixture-of-Experts, or reinforcement learning (GRPO, PPO, RLVR). Also considered JAX. Open-source contributions. Published research. Experience with GPU clusters at the scale described above. Interview process Hiring-manager screen — 25 minutes. Recruiter screen — 15 minutes. Machine-learning coding interviews — two sessions, 45 minutes each. Machine-learning system-design interview — 45 minutes. Technical deep-dive with the Director of AI Research — 60 minutes. Final interview — 30 minutes. Offer. Base salary: $147,000–$220,000 + strong bonus programmes in addition to base salary. Hybrid in Seattle, Washington. On-site presence is required. Fully remote is not available. Visa sponsorship is available. Application This search is managed by Intelix.AI. Contact: Hasan Mohammad — .