Software Engineer, AI Agents

Foresite Labs; San Francisco (CA); Hybrid; USD 200,000 - 240,000; Full time

Benefits offered by this job

Competitive equity

Healthcare benefits

Hybrid/remote flexibility

Generous PTO

Job summary

Foresite Labs is seeking a software engineer to build end-to-end agent loops, tool calling, and orchestration for production use in our data pipelines and ML platforms.

You will collaborate with ML engineers, scientists, and bioinformaticians on a small senior team, shipping full-stack features and production-grade infrastructure. Hybrid/remote flexibility is offered along with competitive compensation.

Qualifications

• 5+ years of professional software engineering in production systems.
• Hands-on experience building LLM/agent systems.
• Proficiency in TypeScript and at least one backend language (Python/Go/Java).
• Familiar with cloud platforms and infra-as-code tooling.
• Comfort with Unix, Docker, and CI/CD processes.

Responsibilities

• Build agent loops end-to-end including tool calls and memory.
• Create eval and observability harness with tests and metrics.
• Turn scientific workflows into actionable agents.
• Ship full-stack features with React/Tailwind and backend services.
• Launch production-grade data pipelines and ML infrastructure.
• Use AI-native tooling to move fast while ensuring quality.

Skills

Agent loops in production

LLM/agent systems

TypeScript

Python/Go/Java

Ownership mindset

Tools

AWS

GCP

Azure

Terraform/CDK/Pulumi

Docker

CI/CD pipelines

Job description

Foresite 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.

The Role

We're hiring a software engineer to help create the data pipelines, machine learning infrastructure, and agentic systems that power our science. On the agentic side, that means writing the code that runs the loop an AI agent operates inside, not one-off prompts — designing how agents plan, call tools, orchestrate sub-agents, keep memory, check their own work, and decide when they're done, then shipping them into production to do real work across our genetics and drug-discovery pipeline. This is \"loop engineering\": the model writes the prompts; you build and harden the machinery around it.

It's a full-stack, high-ownership role on a small senior team. You'll take systems from a blank repo to production and work shoulder-to-shoulder with ML engineers, computational biologists, and scientists.

What You’ll Do

• Build agent loops end-to-end — tool/function calling, planning, sub-agent orchestration, memory, and control flow that runs reliably and unsupervised


• Build the eval and observability harness — the tests, metrics, tracing, and guardrails that make agentic systems trustworthy in production


• Turn scientific and operational workflows into agents that take real action across our platform


• Ship full-stack features: React/Tailwind front ends and backend services that put these agents in front of scientists


• Design and launch production-grade systems, services, data pipelines, and machine learning infrastructure from scratch


• Use frontier AI-native development tools (e.g. Claude Code) to move fast


• Uphold engineering standards through code review, testing, and peer mentorship

What You’ll Bring

• 5+ years of professional software engineering, with greenfield systems you've shipped to production


• Hands-on experience building LLM/agent systems in production — agent loops, tool calling, RAG, and evals (frameworks like LangChain, Pydantic AI, or equivalent)


• Fluency in TypeScript plus a modern backend language (Python, Go, or Java)


• Working knowledge of AWS/GCP/Azure core services and infrastructure-as-code (Terraform, CDK, or Pulumi)


• Comfort in Unix, Docker, and CI/CD pipelines


• Early-stage execution mindset and strong ownership


• Clear communication across technical and non-technical audiences

Nice to Have

• Experience with LLM eval / observability tooling (e.g. LangSmith) and prompt/loop iteration at scale


• Multi-agent orchestration in production


• Interest in biology, genetics, or human health — no life-sciences background required

Why Foresite Labs

• Build frontier agentic products that measurably accelerate real drug discovery


• Greenfield work, end-to-end ownership, and architecture decisions without bureaucracy


• A small, senior team working directly across software, ML, and biology


• Competitive base of $200,000–$240,000, meaningful equity, comprehensive healthcare, generous PTO, and hybrid/remote flexibility

Salary range: $200,000 - $240,000

Foresite Labs is an equal opportunity employer.

We thrive on diversity and collaboration.