Member of Technical Staff - Generalist

Job Description

As a Founding Generalist Engineer at Trajectory, you will craft the product experience that makes continual learning legible and intuitive.

You will own the SDK
, API surfaces
, and integration infrastructure that help customers understand, debug, and trust continually improving models. This includes trajectory visualization, evaluation workflows, monitoring dashboards, and the core product interfaces that sit on top of our leading RL infrastructure.

You’ll work directly with the founders and industry-leading design partners (Series B+ AI vertical product companies) to translate frontier RL systems into a clean, developer-first product experience. You will help define the visual language, interaction patterns, and product philosophy of Trajectory.

We are building the interface for continual learning
. This role sets that bar.

• Strong full-stack or backend engineering experience
• Experience building AI-powered products or agent systems - you actively experiment with new frameworks for fun
• Experience building developer-facing products or SDKs
• Experience with data pipelines, telemetry systems, or event infrastructure
  
  Ability to move quickly in a zero-to-one environment

• Experience building observability, tracing, or monitoring systems
• Experience at early-stage developer tooling startups
• Strong product instincts and ability to work directly with customers
• Experience owning SDK design and developer ergonomics

Trajectory was founded by three Stanford alumni - Michael (Deep Mind Robotics Reasoning), Arjun (RL post-training at Apple), and Ronak (Windsurf/Deep Mind; trained SWE-1, the coding model that learned from real product signal and beat the labs). Their work showed the future: products will own models that continually learn from real user workflows.

Trajectory makes that plug-and-play. We use live product telemetry to RL-train custom agentic models - no synthetic environments, no hand-crafted rewards.

Trajectory is founded by a team of ex-Deepmind, OpenAI, Meta, Apple, Mosaic, Adept, and Windsurf RL researchers, raised $15M led by Conviction, backed by Fei-Fei Li, Jeff Dean, and founders of Notion, Braintrust, Modal, Hugging Face, and Dropbox. Working with some of the leading AI companies in the world to power their core agent products.

We’re building our team of founding Members of Technical Staff to design the frontier of continually learning systems.