Software Engineer, AI Agents

Senior Software EngineerSan Francisco, CAForesite Labs is a translational R&D team that derives insights from precision measurement and population-scale biology and genetics to address unmet clinical needs. We use human genetics to systematically dissect and understand human disease biology and develop and critically evaluate therapeutic hypotheses. We engage in translational research, transforming basic insights into therapeutic opportunities. Our work supports drug discovery and company formation, and provides the core around which new ideas are realized and incubated. We offer competitive salaries, excellent benefits, a flexible work environment, and the opportunity to learn from top thinkers in various disciplines. Foresite Labs is headquartered in San Francisco and Boston.What You'll DoBuild from scratch. Design, implement, and own production-grade software systems, services, data pipelines, internal tools, often starting from scratch and evolving them through MVP, scale-up, and sustained operation.Ship features end-to-end. Work across the stack, with meaningful ownership of frontend applications built in React and Tailwind CSS as well as backend services and APIs, to deliver product value quickly and iterate with feedback.Create polished user experiences. Translate ambiguous user and business needs into intuitive, performant interfaces that make complex scientific and operational workflows easier to use.Use modern AI-native development workflows and agentic coding tools, such as Claude Code or Codex, to accelerate prototyping, implementation, refactoring, and debugging.Uphold high engineering standards. Lead code and design reviews, establish testing and monitoring best practices, and collaborate with and mentor peers in clean, maintainable software.Collaborate broadly. Pair with machine learning engineers and scientists, computational biologists, and portfolio company founders to translate scientific or business goals into robust technical solutions.What You'll Bring5+ years of professional software engineering experience, including shipping greenfield systems you personally bootstrapped and supported in production.Fluency in TypeScript and at least one modern backend language (Python, Go, Java, etc.), with strong experience building production full-stack applications.Working knowledge of AWS (or GCP/Azure) core services and patterns—VPC, IAM, ECS/EKS/Lambda, RDS, S3—and experience expressing infrastructure as code with Terraform, CDK, or Pulumi a plus.Comfort navigating Unix environments, containers (Docker), and CI/CD pipelines (GitHub Actions, GitLab, or similar).Hands-on experience with LLM systems and agentic application frameworks, including familiarity with tools such as LangChain and Pydantic AI, and an understanding of how to build production-oriented workflows involving tool use, structured data, multi-step reasoning, iterative loops, testing, and orchestration.Mindset for early-stage execution: bias for action, ownership of ambiguous problem spaces, and ability to wear multiple hats without extensive support structures.Excellent written and verbal communication skills; you explain complex ideas clearly to technical and non-technical partners.Why Foresite LabsImpact. Your code will accelerate discovery and bring novel therapeutics closer to patients and will help AI driven scientific innovation.Autonomy. Small, senior teams give you room to architect and own end-to-end solutions without heavy bureaucracy.Learning. Work at the intersection of software, cloud infrastructure, and biology alongside experts in each domain.Flexibility & Benefits. Competitive salary and equity, comprehensive healthcare, generous PTO, and hybrid/remote options aligned to our SF or Boston hubs.Ready to build? Apply today and help us create the software foundation that powers the next generation of companies advancing biotech and scientific innovation.Location: San Francisco, CASalary range: $185,000 - $221,400Foresite Labs is an equal opportunity employer. We thrive on diversity and collaboration.