Trajectory

Trajectory

Member of Technical Staff - Research

San Francisco · Staff+

Sponsorship not specifiedDetected 57 days ago
Machine LearningPyTorchLLMsResearchExperimental Design

About the role

  • AI is the most capable software ever built, and the least able to learn.
  • Every valuable correction and edit that happens in a product evaporates at the next session.
  • A few teams have closed this gap by hand-coupling their models to their products: Composer, Claude Code, Windsurf SWE-1.

Responsibilities

  • 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.

Requirements

  • Experience training or serving large language models
  • Proficiency in PyTorch, JAX, or similar ML frameworks

Nice to have

  • 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

Company info

  • our platform unlocks the signal already sitting in product use, so companies can continuously post-train large-scale agentic models that outperform the frontier.
  • Working with leading AI companies, including Decagon, Clay, Harvey, Mercor, and Rogo.
  • Founded by researchers from Deepmind, OpenAI, Meta, Apple, Amazon, and Scale. $15M led by Conviction, with Fei-Fei Li, Jeff Dean, and founders of Notion, Braintrust, Modal, Hugging Face, and Dropbox.
  • 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.

This listing is sourced directly from Trajectory's careers page and normalized into a canonical job model.