Member of Technical Staff - Research
- Location
- San Francisco, CA · On-site
- Job type
- Full-time
- Level
- Mid-level
- Education
- Master's degree
- Listed
- 23 days ago
Skills & highlights for this role
- LLM training
- reinforcement learning
- PyTorch
Also useful
- JAX
- RL environments
- LLM evaluation suites
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.
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.
Required Qualifications
- 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
Preferred
- 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
About Trajectory
Trajectory is a research and product lab creating the platform for continual learning.
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.
Trajectory is the first scalable approach for every company: 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.
From Trajectory's careers page, first listed on Rolev.ai on October 17, 2026. Rolev.ai is not the employer.
How Rolev.ai helps with this application
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Common questions
Where is the Member of Technical Staff - Research job at Trajectory located?
This Member of Technical Staff - Research position at Trajectory is located in San Francisco, CA (On-site). Always check Trajectory's application page for specific state eligibility or relocation policies.
What qualifications are required for Member of Technical Staff - Research at Trajectory?
For the Member of Technical Staff - Research role, Trajectory highlights a master's degree; experience with LLM training, reinforcement learning, PyTorch. Rolev.ai can score your existing resume against these requirements and show any skill gaps before you apply.
How do I apply for the Member of Technical Staff - Research position at Trajectory?
This listing links directly to Trajectory's Ashby application page. You can apply directly on Trajectory's site, or use Rolev.ai to check your resume fit, generate a zero-hallucination tailored resume and cover letter for this posting, and autofill the Ashby application form in 1 click with the Rolev.ai Chrome extension. You always review the form and press Submit yourself.