Reinforcement Learning jobs

About xAI

xAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge.

Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity.

We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important.

All engineers and researchers are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates.

About the Role

The post-training team at xAI transforms powerful pre-trained models to become steerable, versatile, and capable of understanding and addressing real-world challenges.

As a post-training researcher/engineer, you will enhance the model's instruction-following capability and general usefulness to fulfill our mission – developing AI systems that can accurately understand the universe, create new knowledge, and improve themselves through interactions.

Focus

• Creating and driving research agenda to advance model quality.
• Improving data mixtures by building data collection pipelines and developing data generation techniques.
• Creating generalizable reward models and developing novel reinforcement learning algorithms.
• Designing and implementing robust model evaluations.
• Designing and implementing large-scale model training frameworks.
• Collaborating with pre-training, reasoning, data, multimodal, applied, product efforts to push the frontiers of model capability.

Ideal Experiences

• Expert in ML and fine-tuning large language models.
• Track record in leading research that significantly impacts AI advancement.
• Experience in data-driven large language model behavior improvements.
• Experience in advanced reinforcement learning or inference-time search techniques.
• Experience in developing benchmarks or large-scale distributed machine learning systems.
• Experience in model optimizations under complex setups (e.g., multi-modality, multi-context, multi-agent, long-horizon tasks, diverse user preference/feedback).

Location

The role is based in the Bay Area [San Francisco and Palo Alto]. Candidates are expected to be located near the Bay Area or open to relocation.

Tech Stack

• Python
• Jax
• Rust

Interview Process

After submitting your application, the team reviews your CV and statement of exceptional work. If your application passes this stage, you will be invited to a 15-minute interview (“phone interview”) during which a member of our team will ask some basic questions. If you clear the initial phone interview, you will enter the main process, which consists of four technical interviews:

1. Coding assessment in a language of your choice.
2. 2 x post-training technical sessions: These sessions will be testing your ability to formulate, design and solve concrete problems in post-training. It can be research or engineering, depending on background/experience. 
3. Meet the Team: Present your past exceptional work and your vision with xAI to a small audience.

Our goal is to finish the main process within one week. All interviews will be conducted via Google Meet.

Annual Salary Range

$180,000 - $440,000 USD

xAI is an equal opportunity employer and does not unlawfully discriminate based on race, color, religion, ethnicity, ancestry, national origin, sex (including pregnancy, childbirth, or related medical conditions), sexual orientation, gender, gender identity, gender expression, age, disability, medical conditions, genetic information, marital status, military or veteran status, or any other applicable legally protected characteristics. 

Qualified applicants with arrest or conviction records will be considered for employment in accordance with all applicable federal, state, and local laws, including the San Francisco Fair Chance Ordinance, Los Angeles County Fair Chance Ordinance for Employers, and the California Fair Chance Act. 

For Los Angeles County (unincorporated) Candidates:

xAI reasonably believes that criminal history may have a direct, adverse and negative relationship on the following job duties, potentially resulting in the withdrawal of a conditional offer of employment: 

• Access to information technology systems and confidential information, including proprietary and trade secret information, and/or user data;
• Interacting with internal and/or external clients and colleagues; and
• Exercising sound judgment.

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