Software Engineer

Reposted One Month Ago
San Francisco, CA, USA
In-Office
Mid level
Artificial Intelligence
Scale AI for reinforcement learning environments
The Role
Build features for reinforcement learning environments, design UI and backend services, automate testing, and iterate features based on AI feedback.
Summary Generated by Built In

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.

Skills Required

  • Experience with Typescript, React, and NodeJS
  • Familiarity with Postgres and Redis
  • Ability to implement automated testing and QA workflows
  • Experience in building UI components

Idler Compensation & Benefits Highlights

  • Equity Value & Accessibility Equity is presented as a meaningful component of total compensation, with explicit bands highlighted across company and YC profiles. This positions ownership as a core part of the package for early hires.
  • Fair & Transparent Compensation Public job listings disclose salary ranges and core benefits, signaling a transparent approach to pay. Several sources indicate the company aims to compete on compensation for experienced roles.
  • Wellbeing & Lifestyle Benefits Day-to-day costs are reduced through free daily meals, snacks/coffee, team events/offsites, relocation assistance, and top-end equipment. These on-site perks are consistently called out across employer profiles.

Idler Insights

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The Company
HQ: San Francisco, California
6 Employees
Year Founded: 2025

What We Do

Idler builds reinforcement learning environments that teach AI models to code at expert human levels. We create training environments based on real-world coding scenarios that prepare models for the complex challenges they'll face in production.

Why Work With Us

You'll be joining a team that's expanding quickly, get direct access to AI researchers at frontier labs, and be put in a position to grow as fast as you can handle.

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Idler Offices

OnSite Workspace

All employees work in person out of our office in the Dogpatch neighborhood of San Francisco.

Typical time on-site: None
HQSan Francisco, California
Dogpatch

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