Character.AI jobs

Principal Research Engineer role at Character.AI focused on post-training systems for large language models. Responsibilities include leading technical vision for data, algorithms, and infrastructure across alignment, optimization, and training—combining deep technical expertise with team mentorship and cross-functional leadership. Requires PhD in ML/CS or equivalent, experience leading technical projects at scale, and deep modern ML expertise. Compensation $275k–$400k annually. Based onsite in Redwood City, CA.

Research Engineer (Multimodal) at Character.AI building and training video and image generation models. Requires PyTorch, video/image architecture expertise, distributed training (FSDP, DeepSpeed), data pipelines, preferably publications. Salary $225–400k. Remote from Redwood City, CA.

Software Engineer (Backend/Applied ML) for Safety & Integrity team at Character.AI, designing systems to detect and mitigate safety risks in human-AI interactions. Requires backend architecture, applied ML (content classification, anomaly detection), cross-functional collaboration. Salary $150–300k. Remote from Redwood City, CA.

Software/ML Engineer for Discovery, Recommendation & Search at Character.AI building ML backends for recommendations, ranking, and search. Requires 5+ years experience, Python/Golang, GCP/AWS, ML frameworks, CI/CD, data pipelines. Salary $200–300k. Remote from Redwood City, CA.

Backend Engineer role building scalable systems at Character.AI (20M+ monthly users), a unicorn entertainment AI platform. Requires 5+ years backend experience with Python, Java, or Go; PostgreSQL/NoSQL; REST/GraphQL APIs; microservices; Docker/Kubernetes. Salary $180–300k. Remote from Redwood City, CA.

Software Engineer (Monetization) at Character.AI designing payment flows, subscriptions, and in-app purchases. Requires TypeScript/React/React Native/Tailwind, Python/Golang for backend, consumer product experience, payments/IAP/subscription expertise. Salary $150–300k. Remote from Redwood City, CA.

Software Engineer (Core Product) at Character.AI building user interfaces and front-end experiences for AI character interactions. Requires TypeScript/React/React Native/Tailwind expertise, front-end/full-stack experience, design systems knowledge, consumer product background. Salary $150–300k. Remote from Redwood City, CA.

Research Engineer (AI Safety & Alignment) at Character.AI conducting safety research, alignment techniques, and adversarial testing for LLMs. Requires PhD or equivalent, GPU/training code experience, data pipelines, transformers, RLHF expertise, safety research focus. Salary $225–400k. Remote from Redwood City, CA.

ML Infrastructure Engineer role supporting research and training infrastructure at Character.AI. Requires 4+ years ML infrastructure experience, GPU cluster management, cloud platforms, tooling for diagnostics. Salary $150–350k. Remote from Redwood City, CA.

Research Engineer (Post-Training) role at Character.AI developing fine-tuning and alignment algorithms for language models. Requires PhD or equivalent, PyTorch/GPU experience, data pipelines, ML fundamentals. Salary $225–400k. Remote from Redwood City or NYC.