Machine Learning Engineer, Safety

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

We are seeking a passionate and innovative Machine Learning Engineer to join xAI’s Applied Safety team, where you will drive the development of cutting-edge ML solutions to ensure compliance with X’s Terms of Service and enhance user safety. In this role, you will own the full machine learning lifecycle, building and deploying models to detect and mitigate threats like abuse, spam, and fraud, while fostering a secure and trusted global digital public square. Ideal candidates are creative problem-solvers who thrive in 0-to-1 environments, prioritize impactful code over documentation, and are excited to apply advanced ML techniques to high-stakes safety challenges. Responsibilities

• Own the end-to-end machine learning lifecycle for safety systems, including data gathering, cleaning, model training, evaluation, and serving at scale
• Develop ML models to detect and remediate violative content in areas like abuse, spam, and child safety
• Integrate models into production systems for Real Time inference and high-throughput processing
• Apply creative problem-solving to build novel ML solutions in uncharted spaces
• Collaborate across engineering, product, and operations to enhance the safety ecosystem
• Lead technical initiatives in ML-driven areas like fraud detection or content moderation

• 5+ years in machine learning engineering or related roles
• Proven experience managing the full ML lifecycle, from data preparation to model serving
• Familiarity with modern data pipelines and ML infrastructure ecosystems
• Enjoyment of 0-to-1 environments, where you trailblaze novel ML solutions, * Prior experience in Trust and Safety or applying ML to content moderation
• Experience applying LLMs to real-world problems, such as natural language understanding or anomaly detection
• Fluency in Python, with knowledge of ML libraries (eg, TensorFlow, PyTorch)
• Background in scalable systems for handling large datasets

Annual Salary Range: $200,000 - $350,000 USD, Base salary is just one part of our total rewards package at xAI, which also includes equity, comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks.