Senior Research Engineer, Model Training / Pretraining

Intelix.AI; Seattle (WA); On-site; USD 147,000 - 220,000; Full time

Job summary

Intelix.AI is seeking a Senior Research Engineer on the model scaling team, reporting to the Director of AI Research. The role covers model training and the supporting infrastructure, with training runs on 600 B300 and 1,000 H100 GPUs in a hybrid Seattle environment.

Responsibilities include building the training stack for distributed training, running scaling experiments, and specializing in CUDA kernels, Mixture-of-Experts, or RL post-training, plus releasing models and code publicly.

Qualifications

• 6+ years of software engineering experience.
• 4+ years of machine-learning infrastructure experience.
• Experience training models from scratch (pretraining) is required; retrieval-augmented generation or fine-tuning only does not meet this.

Responsibilities

• Build and maintain the training stack for distributed model training across GPU clusters.
• Run scaling experiments covering model architecture, data, and optimisation.
• Specialise in one area: CUDA kernels, Mixture-of-Experts, or reinforcement-learning post-training (GRPO, PPO, RLVR).
• Release models, code, and associated research publicly.

Skills

Python

PyTorch

CUDA

Mixture-of-Experts

Reinforcement Learning

Tools

JAX

Job description

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.
• Hiring-manager screen — 25 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 — [e-mail].