Research Engineer, Post-Training (All Industry Levels)

Character.AI; Menlo Park, New York (CA, NY); On-site; USD 100,000 - 160,000; Full time

Job summary

An innovative AI company is seeking a Research Engineer to enhance the performance of state-of-the-art AI models. In this role, you'll fine-tune algorithms and optimize training methods, directly impacting the conversational experiences of millions. Your expertise will help shape AI technology into a companion for daily life, making a significant contribution to groundbreaking advancements. If you're passionate about pushing the boundaries of AI and want to be at the forefront of technology, this is your chance to make a real difference in an exciting and rapidly evolving field.

Qualifications

• PhD or equivalent experience in research required.
• Strong understanding of modern machine learning techniques essential.

Responsibilities

• Develop alignment algorithms and improve model performance.
• Write data pipelines for processing diverse web data.

Skills

Machine Learning Techniques

Data Pipelines

GPU Experience

Alignment Algorithms

Sampling Algorithms

Education

PhD or equivalent research experience

Tools

Kubernetes

Docker

Cloud Services

Job description

Joining us as a Research Engineer on the Post-Training team, you'll be diving into the exciting world of fine-tuning AI models, optimizing their performance, and ensuring they meet the highest standards of quality and efficiency. Your work will directly contribute to our groundbreaking advancements in AI, helping shape an era where technology is not just a tool, but a companion in our daily lives. At Character.AI, your talent, creativity, and expertise will not just be valued—they will be the catalyst for change in an AI-driven future.

About the role

The Post-Training team is responsible for developing our powerful pretrained language models into intelligent, engaging, and aligned products.

As a Post-Training Researcher, you will work across teams and our technical stack to improve our model performance and training methods, including data, compute, and algorithms. You will get to shape the conversational experience of millions of users per day.

Example projects:

• Develop alignment algorithms and loss functions to improve data sample efficiency.
• Write data pipelines to process diverse web data into a format models can ingest.
• Identify quality signals to understand our model’s performance in the real world.
• Design sampling algorithms to improve serving efficiency of large generative models.

Job Requirements

• At least PhD (or equivalent) research experience
• Write clear and clean production-facing and training code
• Experience working with GPUs (training, serving, debugging)
• Experience with data pipelines and data infrastructure
• Strong understanding of modern machine learning techniques (reinforcement learning, transformers, etc)
• Track record of exceptional research or creative applied ML projects

Nice to Have

• Experience with product experimentation and A/B testing
• Experience training large models in a distributed setting
• Familiarity with ML deployment and orchestration (Kubernetes, Docker, cloud)
• Publications in relevant academic journals or conferences in the field of machine learning

About Character.AI

Founded in 2021, Character is a leading AI company offering personalized experiences through customizable AI 'Characters.' As one of the most widely used AI platforms worldwide, Character enables users to interact with AI tailored to their unique needs and preferences.

In just two years, we achieved unicorn status and were named Google Play's AI App of the Year – a testament to our groundbreaking technology and vision.

Ready to shape the future of Consumer AI?

At Character, we value diversity and welcome applicants from all backgrounds. As an equal opportunity employer, we firmly uphold a non-discrimination policy based on race, religion, national origin, gender, sexual orientation, age, veteran status, or disability. Your unique perspectives are vital to our success.