Founding Research Engineer, Model Training
CellType (YC W26) · New York, NY · 3 mo ago
On-siteEngineering$150k–$250k/yrFull-time
About the role
This role sits at the boundary of research and engineering. You will work on training, post-training, evaluation, performance optimization, and the systems needed to support all of that.
Responsibilities
- Build and improve training and post-training systems for biological foundation models and agentic model workflows
- Design and run experiments across supervised fine-tuning, reinforcement learning, tool use, evaluation, and model behavior optimization
- Build and maintain distributed RL and post-training infrastructure
- Improve reliability of rollout, evaluation, and reward pipelines
- Own critical parts of the model training stack, including performance, reliability, observability, and debugging
- Investigate and resolve issues across the full stack, from training dynamics and evaluation infrastructure to distributed systems and hardware bottlenecks
- Profile and eliminate performance bottlenecks across GPU, networking, and storage layers
- Build clean abstractions for experiments, model evaluation, and distributed training workflows
- Improve training efficiency, stability, and throughput
- Work closely with founders and domain experts to translate biological problems into model tasks, environments, and evaluation frameworks
- Help turn research improvements into real product and customer advantage
Requirements
- Have hands-on experience training or materially improving serious LLM or generative ML systems
- Have strong software engineering and distributed systems fundamentals
- Have deep experience with Python and modern ML frameworks such as PyTorch, JAX, or equivalent systems
- Have experience with reinforcement learning or post-training methods
- Have built evaluation systems for tool-using or open-ended models
- Have a deep understanding of GPU execution constraints and memory trade-offs
- Have experience debugging performance issues in production ML systems
- Can reason about system-level trade-offs between latency, throughput, and cost
- Have a track record of owning critical production infrastructure
- Can balance research exploration with engineering implementation
- Have experience with distributed systems, large-scale training, or performance-sensitive ML workloads
- Care about code quality, testing, performance, and maintainability
Qualifications
- Communicate clearly and collaborate well under both normal and high-pressure conditions
- Want broad ownership rather than a narrow role boundary
Skills
- Distributed Systems
- Machine Learning
- Reinforcement Learning (RL)
Benefits
- Competitive salary range: $150K - $250K
- Stock options
- Flexible working hours
- Professional development opportunities
Pay
- $150K - $250K
Schedule
- Full-time