Senior Software Engineer, RL Environments

Pareto • San Francisco, CA

2d • $245,000 - $300,000 • Hybrid

About The Position

Humanity is in a virtuous cycle: human insight improves AI, and better AI expands what people can do. Sustaining it depends on the one input that can't be automated: expert human judgment. At Pareto, we build the platform that turns that judgment into the data, evals, and RL environments frontier models learn from. We work with leading frontier labs like Anthropic and GDM, and we give skilled people everywhere a way to shape the future of AI and share in what it creates. This RL environment and human-data infrastructure is already in production. Our job now is to scale it.

You'll own the RL environments frontier labs train on, end to end. Scope the problem with the requester, build the image and the tools inside it, write the graders that score it, ship it into the customer's platform, and keep it healthy once it's running. You sit between Pareto's engineering team and the researchers at the labs we work with, close enough to both that you can tell when a training goal and a buildable spec have drifted apart.

Nobody will hand you a finished spec. You'll get a research problem, define what gets built, and stay with it after it lands. In your first year, good looks like environments that ship faster than the last one did, because you invested in the build and release path instead of hand-rolling each delivery. What you build becomes training signal. That's the reason the ownership runs all the way through production.

Requirements

• 7+ years of experience building production systems.
• Production Python or TypeScript experience. Strong functional-language background is also valuable.
• Experience building and shipping containerized services (Docker layering, dependency pinning, reproducible images).
• Fluent use of coding agents and the ability to review their output.
• Experience owning production systems, including incident resolution and post-mortem documentation.
• Familiarity with cloud infrastructure (containers, managed databases, deploy paths on AWS or other major clouds).
• Based in the US and able to travel to the Bay Area as needed.

Responsibilities

• Own the environment, end to end. Build industry-leading RL environments and MCP tools that power post-training loops for frontier labs.
• Scope with the requester. Partner closely with research labs, turn a rough training goal into a spec you can build against, and push back early when the ask won't produce usable signal.
• Ensure production health. Investigate failed tasks and jobs and take the lead when a delivery pipeline degrades.
• Leverage the platform. Implement automated image builds and release notes, spec-first design, CI gates, review harnesses. Aim for the next environment to cost a fraction of the last one.
• Integrate signal back into product. Identify when the platform falls short of what a lab needs and get that gap onto the roadmap.

Benefits

• Base salary $245K–$300K
• Equity is part of the package at every level.
• Environments you build become the training signal for models at Anthropic and GDM.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed