Pre-training Research Engineer

About The Role

As a Pre-training Research Engineer, you'll focus on model implementation, pertaining and scaling, and improving the quality of our byte-native and multimodal foundation models. You'll build and iterate quickly on research ideas, contribute production-grade training code and infrastructure, and help deliver high-quality base models that can serve real-world use cases at scale.

Key Responsibilities

• Train large byte-native and multimodal foundation models across massive, heterogeneous corpora
• Implement and evaluate new model architectures, training objectives, and optimization methods
• Develop stable pre-training recipes and run scaling experiments for novel architectures
• Conduct ablations and analyze training dynamics, model behavior, and base-model quality
• Work with data and distributed training engineers to improve training efficiency, reliability, and scalability

Must-Haves

• 5+ years of experience in machine learning research or engineering, with a proven track record of developing and pre-training large language or multimodal foundation models
• Strong general software engineering skills, with the ability to write robust and performant training code
• Solid understanding of deep learning fundamentals and modern pre-training methods and literature
• Ability to quickly implement research ideas and evaluate them using clear baselines, ablations, metrics, and analysis
• Hands-on experience running training workloads in GPU-based environments, with familiarity with distributed training
• MS in Computer Science, Machine Learning, Artificial Intelligence, Mathematics, or a related field

Nice-to-Haves

• PhD in Computer Science, Machine Learning, Artificial Intelligence, Mathematics, or a related field
• Extensive experience with the JAX, Flax, and XLA stack
• Experience with multi-node pre-training using systems such as FSDP, ZeRO, or Megatron
• Experience developing training recipes, ablations, or scaling experiments
• Experience owning end-to-end training and evaluation pipelines with monitoring and reproducibility

Benefits

• Medical, dental, and vision insurance
• 401k plan
• Daily lunch, snacks, and beverages
• Flexible time off
• Competitive salary and equity