# Prompt Engineer

**Company:** [Cantina](https://hotfix.jobs/companies/cantina)
**Location:** Los Angeles, CA, San Francisco, CA
**Role:** ML Engineering
**Salary:** $150k – $180k/yr
**Experience:** 3+ years
**Skills:** LLMs, Prompt Engineering, Python, Datasets, Model Evaluation, Behavioral Evaluations, Synthetic Data, Multi-Step Prompts, System Prompts
**Posted:** 2026-01-29

> Designs and optimizes prompts for social AI characters to ensure realistic personality, emotion, and behavior across text, voice, image, and video. Collaborates with product, design, and engineering on scalable systems; requires 3+ years LLM experience and Python familiarity.

## Job Description

## What You’ll Do
- Define and author core behavior system prompts that shape how Cantina bots express personality, emotion, dialect, and social behavior across text, voice, image, and video.
- Identify key personality traits that make AI personas compelling, and create datasets and prompt structures that reliably reproduce those traits.
- Prototype new bot traits and product features through prompt engineering and iterate based on qualitative and quantitative evaluation.
- Balance short-term feature development with long-term behavioral consistency and quality across the Cantina ecosystem.
- Collaborate with research to build and maintain behavioral evaluations that measure bot performance, personality fidelity, and interaction quality over time.
- Partner with product, design, and engineering to translate creative intent and user feedback into scalable prompt systems.
- Review, refine, and evolve prompts as they move into production, helping establish best practices and launch criteria.
- Track emerging issues in bot behavior, prioritize improvements, and drive prompt-level solutions in ambiguous or high-impact areas.
- Document model quirks, prompting strategies, and guidelines to scale prompt development across teams.
- Support research and ML in our training efforts by delivering meta-prompts for our synthetic data pipelines and evaluating new model behavior.

## What You’ll Bring
- 3+ years of experience prompt engineering and developing LLM-based features end-to-end.
- Strong experience writing, testing, and iterating on complex multi-step and system-level prompts.
- Deep understanding of LLM capabilities, limitations, and quirks, with strong intuition for how input design shapes model behavior.
- Experience creating datasets and evaluating model outputs in collaboration with ML or product teams.
- Strong grounding in psychology, sociology, linguistics, or related fields as they relate to personality, behavior, and dialect.
- Methodical, hypothesis-driven approach to experimentation and iteration.
- Ability to manage multiple initiatives, prioritize effectively, and operate independently in ambiguous, fast-moving environments.
- Excellent communication skills, with the ability to explain prompt design decisions to technical and non-technical stakeholders.
- Comfortable communicating with executive-level stakeholders.
- Basic Python familiarity and comfort navigating unfamiliar codebases.

## Compensation
**Anticipated annual base salary range: $150,000-$180,000.**

## Benefits
- Competitive salary and generous company equity
- Medical, dental, and vision insurance – 99.99% of premiums covered by Cantina
- 42 days of paid time off, including: 15 PTO days, 10 sick days, 15 company holidays, 2 floating holidays
- Generous parental leave & fertility support
- 401(k) retirement savings plan
- Lifestyle spending account – $500/month
- Complimentary lunch and snacks for in-office employees
- One Medical membership, and more

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