Most job posts are designed to collect as many applications as possible.
This is not one of them.
At Simplify, we work directly with startup founders to help them hire for high-priority roles.
We're partnering with a top AI training lab in San Francisco to hire a junior software engineer — and they pay like it's a senior role: $300K base + equity + bonus, for new grads.
About the company
One-liner: Building high-fidelity RL environments used to train frontier AI models on real software-engineering work
Stage: 11–50 people, HQ in SF. They work directly with the top AI labs — their environments are used to train state-of-the-art models.
Today, AI models learn coding from static datasets and toy problems. This team builds the realistic, simulated engineering environments — long-horizon tasks, real tooling, real failure modes — that frontier labs use to train and evaluate the next generation of coding agents.
What you'll work on
Design and build reinforcement-learning tasks and environments for software-engineering challenges
Own the full lifecycle: from task concept through evaluation against frontier models
Evaluate coding-agent outputs and identify subtle failure patterns
Build Python-based systems, harnesses, and tooling around model training and evals
Work with Docker/Linux environments that mirror real engineering work
Own problems end-to-end in a small, fast-moving team
Must-have
Strong Python skills
Experience working with the latest AI tools and models
Exceptional problem-solving ability — strong technical fundamentals and intuition for AI model behavior
Able to work independently
In person in San Francisco
Nice to have
ML or AI experience (e.g., you've trained your own models) — not required
Strong math/CS background (competitions like USACO/ICPC/olympiads)
Competed in quiz bowl, debate, robotics
Impressive personal projects
Why join
$300K base + equity + bonus — at the junior level
Your work directly shapes how frontier AI models learn to do real engineering
Small fast moving team, no bureaucracy — high ownership from day one
Work at the frontier of RL, agents, and evaluation with the top AI labs as your customers
Seniority level
Entry level
Employment type
Full-time
Job function
Engineering and Information Technology
Industries
Software Development
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