Software Engineer

Sim
San Francisco, California, United StatesFull-time$210,000–$260,000Posted Aug 26, 2026

About the role

Our mission is to automate knowledge work. The first step in our journey is to build the best tool for teams to build agents.

Sim is talent-dense. We're looking for special people who are mission-driven, passionate, and creative.

About the Role

The agent harness is Sim. It's the agent that builds workflows, tables, creates knowledge bases, and does everyday tasks. As a member of this team, you'll build the agent that builds everything else: how it plans, calls tools, uses memory, recovers from failure, and runs reliably at scale for 100,000+ builders.

You may be a fit if

  • You can think clearly about LLM behavior (tool calls, context, retries, evals) and you can turn that intuition into robust infrastructure.

Compensation

$210K–$260K base plus 0.2%–0.8% equity.

Applying

If there appears to be a fit, we'll reach out to schedule 1-2 short technicals. After, we'll schedule an onsite in our office, where you'll work on a small project, discuss ideas, and meet the team.

Equal Opportunity

Sim is committed to creating an inclusive environment for all employees. We celebrate diversity and are committed to creating an inclusive environment for all team members. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

Responsibilities

  • Build the agent that creates workflows, tables, and knowledge bases
  • Develop infrastructure for LLM behavior and tool calls
  • Ensure reliability and scalability for 100,000+ builders

Qualifications

  • Ability to think clearly about LLM behavior
  • Experience with robust infrastructure development

Benefits

  • Equity

Skills mentioned

Generative AILarge Language ModelsAI AgentsTool CallingRetrieval-Augmented GenerationSystem DesignDistributed SystemsBackend DevelopmentAPI IntegrationModel Monitoring

About Sim

Build AI agent workflows in minutes. Connect LLMs to tools like Slack, Supabase, Pinecone, and Gmail to create research agents, support bots, or data transformation agents. Collaborate by inviting your team to your visual canvas.

Technology2-10 employeesSan Francisco, CA