Software Engineer, Backend/Applied ML (Safety & Integrity)

About the Role

We’re looking for a talented and creative Software Engineer to join our Safety Engineering team at Character.AI. In this role, you will be at the forefront of designing, developing, and scaling robust backend systems and leveraging applied machine learning to tackle critical integrity and safety challenges.

What You'll Do

• Architect & Build: Design, develop, and maintain highly scalable, resilient, and performant backend systems that power our integrity and safety features.
• Lead Complex Solutions: Lead the technical design and implementation of backend solutions for detecting, preventing, and mitigating integrity risks, including traditional issues and emerging threats related to Generative AI.
• Apply Machine Learning: Conceptualize, develop, deploy, and iterate on machine learning models and algorithms for content classification, anomaly detection, risk scoring, behavior analysis, and Generative AI safeguards.
• Cross-Functional Collaboration: Work closely with product managers, data scientists, AI researchers, security teams, and operations to deliver impactful integrity systems.
• Technical Strategy & Roadmap: Drive the long-term technical vision and roadmap for backend integrity systems and applied ML capabilities.
• Mentorship & Leadership: Provide technical guidance and mentorship to other engineers on the team and across the organization.
• Champion Best Practices: Advocate for and implement best practices in software engineering, distributed systems design, data engineering, and ML model lifecycles.
• System Optimization: Continuously analyze and improve the performance, scalability, reliability, and cost-effectiveness of existing integrity platforms and ML models.
• Stay Current: Keep abreast of emerging threats, new technologies, and advancements in backend engineering, distributed systems, and Generative AI safety research.

Who You Are

• 8+ years of professional software engineering experience, with a strong emphasis on backend systems development.
• Bachelor's, Master's, or PhD degree in Computer Science, Engineering, or a related technical field.
• Proven track record of designing, building, and operating complex, large-scale, and highly available distributed systems.
• Expertise in one or more backend programming languages such as Python, Go, Java, or C++.
• Hands-on experience applying machine learning techniques to real-world problems, specifically addressing integrity, trust, or safety challenges.
• Solid understanding of the machine learning lifecycle (data gathering/cleaning, feature engineering, model selection, training, validation, A/B testing, deployment, and monitoring).
• Exceptional problem-solving abilities in ambiguous environments.
• Proven ability to deliver timely results in a fast-paced development environment.
• Strong communication, interpersonal, and leadership skills.

Great Fit If:

• You care deeply about Trust & Safety and see it as a value-add to the business.
• Prior experience in a dedicated Trust & Safety, Integrity, or Risk engineering team.
• Contributions to open-source projects or publications in relevant fields.
• Experience leading large, cross-cutting technical projects.