Sr. Model Engineer, Mid-Training

Job summary

Responsibilities

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of making life multiplanetary and expanding…

• Scale synthetic coding data to trillions of tokens with large-scale docker verification
• Distill the intelligence of flagship models into flash models through synthetic data generation
• Optimize mid-training data mixtures to boost the ceiling for RL
• Engineer long-context data recipes
• Develop robust and diverse evaluation for mid-training checkpoints

What they're looking for

• Experience writing production-quality code in Python, PyTorch, JAX, Rust, or C++
• Experience training large models (e.g., pre-training, post-training, fine-tuning, or RL training of neural networks with 1B+ parameters)
• Familiarity across all kinds of scaling laws
• Strong ability to design ML experiments
• Familiarity with state-of-the-art techniques for curating AI training data for text, image, audio, and video modalities

Tech stack

• Docker
• Python
• PyTorch
• JAX
• Rust
• C++
• Spark
• Ray