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

Character.AI· Technical Staff - Engineering
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Hybrid (Redwood City, CA)$150k - $300k + equityFull-timePosted 9mo ago

About the role

Software Engineer to design, develop, and scale backend systems and apply machine learning to address integrity and safety challenges in human-to-AI interactions, leadership and roadmap responsibilities.

Responsibilities

  • 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 sophisticated backend solutions for detecting, preventing, and mitigating a wide array of integrity risks (including content classification, spam, and GenAI-related threats).
  • Apply Machine Learning: Conceptualize, develop, deploy, and iterate on ML models and algorithms for integrity challenges (content classification, anomaly detection, risk scoring, behavior analysis, safeguards for Generative AI).
  • Cross-Functional Collaboration: Work with product managers, data scientists, AI researchers, security teams, and operations to define requirements and deliver integrity systems for GenAI products.
  • Technical Strategy & Roadmap: Drive long-term vision and roadmap for backend integrity systems and applied ML, aligning with GenAI safety concerns and company objectives.
  • Mentorship & Leadership: Provide technical guidance and mentorship to engineers.
  • Champion Best Practices: Advocate for software engineering, distributed systems, data engineering, and ML lifecycle best practices with safety/ethics considerations.
  • System Optimization: Improve performance, scalability, reliability, and cost-effectiveness of integrity platforms and ML models.
  • Stay Current: Keep abreast of threats, technologies, and advancements in backend engineering and GenAI safety research.

Qualifications

  • 8+ years of professional software engineering experience with emphasis on backend systems development.
  • Bachelor's, Master's, or PhD in Computer Science, Engineering, or related field.
  • Proven track record of designing, building, and operating large-scale distributed systems.
  • Expertise in Python, Go, Java, or C++.
  • Hands-on experience applying ML techniques to real-world integrity/trust/safety challenges.
  • Solid understanding of ML lifecycle (data gathering/cleaning, feature engineering, model selection, training, validation, A/B testing, deployment, monitoring).
  • Strong problem-solving, fast-paced delivery, communication, interpersonal, and leadership skills.

Skills

Required:Backend developmentMachine learning applied to trust/safetyDistributed systemsPython/Go/Java/C++

Benefits

  • Top-notch health coverage for you & your family, majority covered
  • Generous 401(K) contribution
  • Paid leave up to 20 weeks for new parents
  • 4 weeks of PTO
  • Daily in-office catering plus monthly Doordash stipend
  • Monthly wellness stipend
Last updated Jul 15, 2026. Interested? Apply on the company site.
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