Senior Backend / Systems Engineer (AI) - San Mateo, CA

About the Role:
We are seeking a Backend / Systems Engineer to help build a flexible, robust, and high-performance backend architecture that serves diverse use cases across customers and product lines. Your work will be critical in enabling our AI engineers, analysts, and data scientists to rapidly prototype, iterate, and deploy workflows, services and data pipelines that leverage large language models (LLMs).

This is a high-impact role that blends backend engineering with thoughtful system design to accelerate product development and real-world impact of AI Systems, in particular LLMs.

What You'll Do:

• Design and build extensible backend systems that support flexible configurations for different customers and content types.
  

• Develop infrastructure that interfaces cleanly with LLMs—enabling prompt engineering, context injection, and modular evaluation workflows.
  

• Build tooling and platforms that enable fast iteration by AI engineers and analysts, including declarative pipelines, parameterized jobs, and reproducible experiments.
  

• Prioritize ease of deployment, integration, and testing—both for internal teams and external partners.
  

• Collaborate closely with product, data, and policy teams to translate nuanced safety needs into scalable, maintainable software systems.
  

What We’re Looking For:

• 3+ years of experience in backend systems or infrastructure engineering.
  

• Strong software engineering skills in Python, Go, Java, or equivalent.
  

• Experience designing scalable APIs, backend systems and data pipelines.
  

• Familiarity with LLM-based systems (e.g., prompt management, context formatting, batch inference, prompt-tuning workflows).
  

• Strong understanding of cloud-native infrastructure (e.g., AWS, Lambda, Kubernetes, CI/CD pipelines).
  

• Passion for building systems that unlock velocity and experimentation for cross-functional teams.
  

Nice to Have:

• Background in trust & safety, or content moderation.
  

• Familiarity with Django, Snowflake, React, Step functions.
  

• Experience with LLM-Ops and DevOps.

Why Join Us?

• Work with a group of renown industry leaders in AI and Online Safety to shape the future of the industry.

• Ample opportunity and support for growth.

• Apply AI technology to real-world business use cases at a significant scale, with blue chip customers

• Work as part of a team where you can know everyone, but don’t have to do everyone’s job.

• Competitive compensation, comprehensive benefits, and hybrid in-office policy.