Software Engineer

About idler

idler is a frontier data research lab. We build the evals and environments that the world's leading frontier labs use to measure and train their models.

After raising a $9m seed round led by Paradigm, we spent the last year developing coding evals for top coding models you know and love. At the same time, we've expanded into other domains besides coding: RSI & Auto-Research, Law, Enterprise Business, Cybersecurity, and others. Now, we are facing more lab demand for our data than we can serve, and are rapidly scaling the team to grow the business.

Our approach to creating training data scales using technology, and all of our data products are built on a unified self-reinforcing platform that learns through experience.

You would be joining a close-knit team that has reached product market fit, and your work would directly help to multiply our revenue.

You can see some of our work here: https://idler.ai/collections

About the role

As a Software Engineer at idler, you’ll build the systems and infrastructure that our entire company relies on. You will solve open-ended, technical challenges with focus on performance, scale, and simplicity. In the era of AI-coding, systems-level thinking and attention to detail is more important than experience with a particular framework or language.

Examples of what you'll do

• Design and build scaleable systems that generate RL environments

• Create agentic QA systems to validate environment quality and fairness

• Work directly with AI researchers at leading labs to understand what makes training data effective

• Handle petabyte scale ETL and orchestrate millions of concurrent jobs

• Support new product lines as we expand beyond coding environments

• Manage our security posture and compliance requirements

What we’re looking for

• 1-10 years of experience writing excellent production software (new grads OK)

• Experience with full-stack applications in a popular programming language

• A meticulous problem solver who creates robust systems under time pressure

Tech stack

Typescript, React, NodeJS, Postgres, Redis, Vercel, Cursor/Claude Code/Codex, Tinker, Modal, AWS, Daytona, GRPO

Details

• In-person in San Francisco

• Competitive salary + meaningful equity

• Free meals in office

• Healthcare, 401(k), 15 days of PTO per year

• Relocation assistance

• Small, ambitious team

This is an in-person role in San Francisco. We're a tight-knit founding team and we play to win. Join us if you like to win too.

About idler

Idler builds reinforcement learning environments that teach AI models to code like 0.01% engineers. Our training environments are based on real-world coding scenarios that frontier models will actually encounter.

We've closed a multimillion-dollar contract with a leading foundation lab (the largest they've issued to date), and demand is outpacing our capacity to deliver. We're scaling fast to build the training data layer for frontier AI. Every breakthrough model will need environments like ours to learn real-world skills at scale.

We're a tight-knit founding team in San Francisco. We move quickly, think deeply about what makes good training data, and play to win. Join us if you want to win too.