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

Location: Hybrid in Redwood City, California, United States

Salary: $150,000–$300,000 per year plus equity

Company

Character.AI develops interactive entertainment and consumer AI products that enable people to connect, learn, and tell stories.

What you will do

• Design, build, and operate scalable, resilient backend systems for integrity and safety features.
• Develop systems that detect, prevent, and mitigate content risks, spam, misuse of generative models, and harmful or biased content.
• Apply machine learning to content classification, anomaly detection, risk scoring, behavior analysis, filtering, bias mitigation, and output monitoring.
• Collaborate with product managers, data scientists, AI researchers, security teams, and operations to deliver Generative AI safety solutions.
• Drive the technical vision and roadmap for backend integrity platforms and applied ML capabilities.
• Mentor engineers and improve system performance, reliability, scalability, and cost-effectiveness.

Requirements

• 8+ years of professional software engineering experience, primarily in backend systems development.
• Bachelor’s, Master’s, or PhD degree in Computer Science, Engineering, or a related technical field.
• Experience designing, building, and operating complex, large-scale, highly available distributed systems.
• Expertise in one or more of Python, Go, Java, or C++.
• Hands-on experience applying machine learning to real-world integrity, trust, or safety challenges.
• Strong understanding of the ML lifecycle, technical problem-solving, communication, and leadership.

Nice to have

• Experience on a dedicated Trust & Safety, Integrity, or Risk engineering team.
• Open-source contributions or publications in relevant fields.
• Experience leading large, cross-cutting technical projects.

Culture & Benefits

• Health coverage for employees and families with most premiums covered.
• Generous 401(k) contribution and up to 20 weeks of paid parental leave.
• Four weeks of paid time off.
• Daily in-office catering, monthly DoorDash stipend, and monthly wellness stipend.
• Commitment to diversity, inclusion, and equal employment opportunity.