Startups · AI

Member of Technical Staff - Research

Trajectory · San Francisco · On-site

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About Trajectory

Research lab and product company building the platform for continual learning. Backed by Bessemer and Conviction.

About the role

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.

What they're looking for

  • 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
More about this role

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

Trajectory is a research and...

Read the full posting on Trajectory's site ↗

Member of Technical Staff

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