Member of Technical Staff - Research

Job Description

As a Member of Technical Staff (Research) at Trajectory, you will design and build the post‑training stack that lets our customers’ models continually learn from real production workflows. You will own end‑to‑end experiments across data, training, and evaluation: shaping telemetry into learnable signals, training and serving custom LLMs and agents, and designing novel algorithms. You’ll work directly with the founders and design partners, make foundational technical and product decisions, and help define both the culture and architecture of a company whose core mission is to enable continually learning intelligence.

• Experience training or serving large language models
• Experience building RL environments or evaluation suites for LLMs
• Proficiency in PyTorch, JAX, or similar ML frameworks
• Strong experimental design skills
• Master’s / research experience

• Background in pre- or post-training RL for LLMs
• Experience with high-performance computing or large-scale clusters
• Contributions to open-source ML research or infrastructure
• Demonstrated technical creativity (research, OSS, side projects)
• PhD (last year of PhD), working on AI / RL open source projects