**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.
Skills Required
- At least 2 years of software engineering experience
- High motivation and strong technical ability
- Ability to take ownership and define problems and plans independently in ambiguous situations
- Ability to work in person at the Palo Alto office
CHAI AI Compensation & Benefits Highlights
The following summarizes recurring compensation and benefits themes identified from responses generated by popular LLMs to common candidate questions about CHAI AI and has not been reviewed or approved by CHAI AI.
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Fair & Transparent Compensation — Pay is considered top-of-market, supported by an explicit hiring policy to beat a candidate’s existing total compensation with heavily all-cash packages. Offers emphasize immediate, simple structures over complex, long-vesting equity.
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Pay Growth & Progression — Compensation is described as scaling for high performers, including performance-based salary increases and materially larger packages for those who pass a rigorous hiring bar. Rapid business growth with a lean team is linked to lucrative payouts for core technical roles.
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Strong & Reliable Incentives — Packages commonly pair substantial base pay with cash bonuses and optional stock components, prioritizing dependable, near-term rewards. The cash-heavy approach is positioned to rival top-paying AI labs and major tech firms.
CHAI AI Insights
What We Do
Palo Alto | Small AI Startup | Top Pay, 100% Cash | Actively Hiring Engineers CHAI AI is a small, 20-person AI startup in Palo Alto building a social AI platform, where millions of people create, share, and chat with AI characters. As of September 2026, CHAI has 10 million active users and $100M in annual recurring revenue, and has grown 3x year-over-year for three consecutive years. We have raised over $55M from investors including AMD and CoreWeave. Our engineers work on hard, production-scale AI problems: Post-training: SFT, reinforcement learning, reranking, and data curation for roleplay LLMs, driven by live user-retention signals. Model serving: routing a fleet of LLMs per conversation turn, and optimizing latency and cost-per-token on our own GPU clusters. Memory: systems that let AI characters remember users across hundreds of conversations. Product: full-stack and backend engineering for a consumer app used by millions. CHAI was founded in 2021 by a team of Cambridge-educated former quantitative traders and researchers. Top pay, 100% cash. We benchmark against total compensation at Meta, Google, and OpenAI, then pay that number in cash instead of equity. Engineering offers range $450K to $900K per year. Candidates can optionally trade part of their cash for stock options. Small team, huge scope. Engineering is 15–20 people with a flat structure. Every engineer owns an entire product area end-to-end, from prototype to production, with clear metrics and direct impact on 10 million users. Real scale, real results. You ship to millions of users and see the effect of your work in the data, whether that is retention, revenue, or model quality. Fast, practical hiring. No leetcode and no recruiter screens. The process is a 20-minute call with our founder or an engineer, a 60–90 minute take-home, and a one-day onsite. We can make an offer within 7 days of first contact. Actively hiring: ML Engineers, Research Engineers (Post-Training), Applied Research Scientists, Infrastructure Engineers, Full-Stack Engineers, and Back-End Engineers. All roles are in person at our Palo Alto office (555 Hamilton Ave). Investor sources: AMD Ventures portfolio: https://www.amd.com/en/ventures/portfolio.html CoreWeave investment announcement: https://www.linkedin.com/posts/coreweave_we-are-happy-to-announce-that-we-are-furthering-activity-7114654559196602368-09n3 Dated company disclosures: https://www.chai-research.com/company-facts/
Why Work With Us
Top pay, 100% cash. We benchmark against total compensation at Meta, Google, and OpenAI, then pay that number in cash instead of equity. Engineering offers range up to $900K per year. Candidates can optionally trade part of their cash for stock options. Small team, huge scope. Engineering is 15–20 people with a flat structure.
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