Researcher, Post Training

About the Role

The next leap in model intelligence won’t come from scale alone — it will come from better post-training and alignment. Cartesia’s Post-Training team is developing the methods and systems that make multimodal models truly adaptive, aligned, and grounded in human intent.

As a Researcher on the Post-Training team, you’ll work at the intersection of machine learning research, alignment, and infrastructure, designing new techniques for preference optimization, model evaluation, and feedback-driven learning. You’ll explore how feedback signals can guide models to reason more effectively across modalities, and you’ll build the infrastructure to measure and improve these behaviors at scale.

Your work will directly shape how Cartesia’s foundation models learn, improve, and ultimately connect with people.

Your Impact

Own research initiatives to improve the alignment and capabilities of multimodal models

Develop new post-training methods and evaluation frameworks to measure model improvement

Partner closely with research, product, and platform teams to define best practices for creating specialized models

Implement, debug, and scale experimental systems to ensure reliability and reproducibility across training runs

Translate research findings into production-ready systems that enhance model reasoning, consistency, and human alignment

What You Bring

Deep knowledge of preference optimization and alignment methods, including RLHF and related approaches

Experience designing evaluations and metrics for generative or multimodal models

Strong engineering and debugging skills, with experience building or scaling complex ML systems

Ability to trace and diagnose complex behaviors in model performance across the training and evaluation pipeline

Nice-To-Haves

Experience with multimodal model training (e.g., text, audio, or vision-language models)

Contributions to alignment research or open-source projects related to model evaluation or fine-tuning

Background in designing or implementing human-in-the-loop evaluation systems

Note: Cartesia participates in E-Verify and will provide the federal government with Form I-9 information to confirm employment eligibility after hire.

More Details

🏢 In-office policy: We’re an in-person team based out of offices in 🇺🇸 San Francisco, 🇬🇧 London and 🇮🇳 Bangalore. We love being in the office, hanging out together, and learning from each other every day.

🌎 Visa sponsorship: We provide visa sponsorship support and assess each circumstance on a case-by-case basis. However, visa sponsorship is dependent on many factors, including the role you are applying for, and the location you are going to be based, and so we can't always guarantee success. Your Recruiter will work with you to understand your visa sponsorship needs from the first call.

🚢 We ship fast. All of our work is novel and cutting edge, and execution speed is paramount. We have a high bar, and we don’t sacrifice quality or design along the way.

🤝 We support each other. We have an open & inclusive culture that’s focused on giving everyone the resources they need to succeed.

Our Benefits (US Employees Only)

💰 Compensation Competitive base salary alongside attractive equity package.

🩺 Health Insurance Fully covered medical insurance along with dental and vision for you and your family.

🧑‍🧑‍🧒‍🧒 Parental Leave 9 weeks paternity & 12 weeks maternity leave

🏦 401(k)

🚆 Commuter Allowance A monthly stipend to help you get to and from the office.

🏖️ Flexible PTO Take as much time as you need to recharge your batteries.

🍲 Meals & Snacks Lunch, dinner and plenty of snacks, provided daily.

🦖 Your own personal Yoshi

Our Commitment to Equal Opportunity

Cartesia is an equal opportunity employer. We consider qualified applicants without regard to race, color, religion, sex, national origin, age, disability, veteran status, genetic information, or any other legally protected status.