idlerResearch Engineer
San Francisco · Full-time
$125K–$400K
Why join idler?
The labs training AI models could come to depend on whoever builds realistic practice environments, and idler, a San Francisco reinforcement learning startup, is building exactly those. Paradigm is among the leads on a $9M seed, bigger than half of seed rounds this half, and the team is ten people or fewer. Seven roles are open, four in engineering, so early hires would shape the environments from the ground up.
JustBacked's take, based on idler's own site and its funding and hiring data.
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.