Senior Research Engineer, Post-Training

**Senior Research Engineer, Post-Training**

**About CHAI AI**

CHAI is a social AI platform where millions of people create, share, and talk to AI characters. As of Sep 2026, it has 10 million active users and $100 million ARR. After receiving over $55M in funding from investors such as AMD and CoreWeave, CHAI AI is actively hiring engineers to expand its team.

**About the team**

Engineering is 15–20 people with a flat structure. High impact on the product, fast iteration, and clear metrics to measure against.

**What you will work on**

Own the pipeline that turns raw roleplay data into better model behavior — SFT, RL, reranking, data curation, whatever it takes. You'll run the loop from eval signal to next training run and decide what to try next.

**You might thrive in this role if you…**

(minimum/Preferred requirements)

- 2+ years of software engineering experience
- High motivation and talented.
- High ownership: comfortable with ambiguity, able to define the problem and the plan rather than execute a predefined spec.
- Able to work in person at our Palo Alto Office.

**Compensation and benefits**

Top pay AI startup in Bay Area. $609,000 – $900,000, paid 100% in cash.

We benchmark against total comp at Meta, Google, and OpenAI — and pay that number in cash, not equity, with the option to trade a portion of cash for stock options.

Health, 401k, unlimited PTO.

**Our interview process**

We run a fast process - an offer can be given within 7 days of first contact.

1. 20 minute phone screen with our founder or engineer
2. 20 minute personality assessment
3. Take home assessment. 60-90 minutes to complete.
4. One day onsite interview.