Founding Harness Engineer

Clera Labs, Inc.; San Francisco (CA); On-site; USD 180,000 - 220,000; Full time

Benefits offered by this job

Founding equity

Job summary

Clera Labs, Inc. is seeking an engineer to build the runtime for AI agents and implement safeguards for safe, reliable operation. You will design context gathering, decision timing, tool selection, and task completion flows in a fast-moving AI startup environment.

You will craft system prompts, develop evaluation and regression tests, and strengthen multi-tenant data separation and approval workflows while collaborating with the founding team and early users to shape the product roadmap.

Qualifications

• Experience shipping tool-using LLM agents beyond demos.
• Hands-on system prompt design with iterative testing.
• Experience building evaluation and regression test harnesses for LLM/agent behavior.
• Understanding safe tool execution, approval workflows, and multi-user data risks.
• Ability to own prototypes through production and explain tradeoffs.
• Experience with LLM agents, tool use, evaluation, and prompt engineering.

Responsibilities

• Design and build the agent runtime for context gathering, deciding when to act, tool selection, approval, and task completion.
• Write and refine system prompts to encourage useful initiative without noisy or risky behavior.
• Build evaluation and regression tests for real tasks, tool use, and failure cases, and catch regressions as prompts change.
• Improve reliability across long-running work, interruptions, and retries.
• Implement safety boundaries, including approval gates and multi-tenant data separation.
• Work directly with the founding team and early users to shape the product.

Skills

LLM agent

System prompts

Regression tests

Safety controls

Tool integration

Multi-tenant data

Tools

Agent tooling

Job description

About the Role

Join an early-stage AI company building an AI coworker for teams. You will develop the runtime and safeguards that help AI agents take useful initiative, work reliably, and handle real tasks safely.

What You'll Do

• Design and build the agent runtime for context gathering, deciding when to act, tool selection, approval, and task completion.

• Write and refine system prompts to encourage useful initiative without noisy or risky behavior.

• Build evaluation and regression tests for real tasks, tool use, and failure cases, and catch regressions as prompts change.

• Improve reliability across long-running work, interruptions, and retries.

• Implement safety boundaries, including approval gates and multi-tenant data separation.

• Work directly with the founding team and early users to shape the product.

What We're Looking For

• Production experience shipping tool-using LLM agents, beyond demos or thin prompt wrappers.

• Hands-on system prompt design, with iterative testing and improvement.

• Experience building evaluation and regression test harnesses for LLM or agent behavior.

• Understanding of safe tool execution, approval workflows, and multi-user data risks.

• Strong ownership across prototyping and production, with the ability to explain technical tradeoffs.

• Experience with LLM agents, tool use, evaluation, and prompt engineering.

Compensation & Benefits

Salary range: $0 to $200,000 USD annually. Founding equity is available; percentage and vesting details are to be determined.

Location

On-site in San Francisco, United States. Candidates should be based in the Bay Area or willing to relocate.