---
title: 'Software Engineer, Agent Harness at Cursor'
canonical: 'https://feeny.ai/job/software-engineer-agent-harness-cursor-san-francisco-5s4q05cj7vqe'
type: 'job'
last_seen: '2026-09-08'
---

# Software Engineer, Agent Harness at Cursor

- **Company:** Cursor
- **Location:** San Francisco, CA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2025-10-27
- **Last confirmed live:** 2026-09-08
- **Apply:** https://jobs.ashbyhq.com/cursor/6e6f5bc2-eb32-40e2-bba9-cfa56479600d

## Job description

Our mission is to automate coding. The first step in our journey is to build the best tool for professional programmers, using a combination of inventive research, design, and engineering. Our organization is very flat, and our team is small and talent dense. We particularly like people who are truth-seeking, passionate, and creative. We enjoy spirited debate, crazy ideas, and shipping code.

## ABOUT THE ROLE

As a Software Engineer on the Agent Harness team at Cursor, you’ll build the core agent behavior and capabilities that power agent experiences across Cursor products. This spans agent orchestration, tools, guardrails, and model behavior tuning—designed as a platform that Cursor engineers can extend and depend on.

Your work will also define the default Cursor agent experience (”Auto”), where users trust us to make the right model choices under real-world constraints.

Example projects include:

- Advancing the agent harness (agent loop, tools, prompts, execution environment, capabilities) used across Cursor products. This would shape and empower experiences like multi-agent coordination.
- Improving the default Cursor agent experience (the “Auto” model setting): making smart model choices based on user needs, model capabilities, and cost appetite.
- Shaping the default Cursor agent’s personality.
- Launching new models on Cursor end-to-end — partnering with foundational model providers and our research team on integration, evaluation, and rollout.

## YOU MAY BE A FIT IF

- You have built complex agentic products or infrastructure.
- You have strong software engineering fundamentals and enjoy shipping production systems.
- You have taste and strong opinions on model and agent behaviors. You stay up-to-date and informed on emerging research and industry trends.
- You make good calls in the gray area: weighing data, user experience, and product taste when there isn’t a single “right” answer.
- Experience building eval datasets or frameworks to understand and improve the performance of AI systems is a plus.
- Experience building products or tools used by other engineers is a plus.

## APPLYING

If there appears to be a fit, we'll reach to schedule 2-3 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.

## #LI-DNI

## About Cursor

## Company Overview
- **One-liner**: Cursor is an AI coding agent and software development environment that enables developers to build, test, and ship software using natural-language instructions and autonomous agents.
- **Entity Type**: Private (pending acquisition by SpaceX/xAI)
- **Headquarters**: San Francisco, California, United States
- **Founded**: 2022
- **Founders**: Michael Truell, Sualeh Asif, Aman Sanger, Arvid Lunnemark

## Core Business
- **Primary industry**: Artificial intelligence, developer tools, software development
- **Target customers**: B2B (enterprise, SMB, individual developers); trusted by over half of the Fortune 500
- **Mission/purpose**: To build the future of software development and help engineers "engineer anything"

## Products & Services
- **Cursor (AI Coding Agent)**: The flagship product — an AI-powered code editor and agent that searches codebases, edits files, runs terminal commands, and completes multi-step programming tasks from natural-language instructions. Available as a desktop IDE, web app, mobile app (iOS), and CLI.
- **Bugbot**: A code-review tool integrated with GitHub pull requests that autonomously detects bugs and issues.
- **Composer Models**: A family of proprietary agentic coding models (Composer, Composer 1.5, Composer 2, Composer 2.5) trained with reinforcement learning for long-running coding tasks.
- **Cursor Automations**: Always-on agents that run on schedules or triggers to build, maintain, and fix software.
- **Cloud Agents**: Agents that run in their own cloud environments to build, test, and demo features end-to-end.
- **Graphite**: A separate product acquired by Cursor (formerly a stack-based Git workflow tool).

## Market Standing
- **Valuation**: $29.3 billion (Series D, November 2025); pending acquisition by SpaceX/xAI at $60 billion (announced June 16, 2026)
- **Key Metric**: $3 billion+ Annual Recurring Revenue (ARR) as of May 2026
- **Notable Investors**: Accel, Coatue Management, Thrive Capital, OpenAI Startup Fund, Google, Nvidia; angel investors include Nat Friedman (former GitHub CEO) and Arash Ferdowsi (Dropbox co-founder)
- **Growth Signals**: Crossed $100M ARR in Jan 2025, $500M ARR by June 2025, $1B ARR by Nov 2025, and $3B ARR by May 2026. Headcount grew from ~300 (2025) to 579 (mid-2026). Expanding into mobile, Jira integration, and enterprise features.

## Competitive Advantages
- **Proprietary coding models (Composer series)** trained with reinforcement learning specifically for software development tasks — a deep technical moat
- **Complete codebase understanding** at any scale, enabling agents to work contextually across large, complex codebases
- **Multi-model flexibility**: Integrates models from OpenAI, Anthropic, Gemini, xAI, and their own models, letting users choose the best tool per task
- **Agentic infrastructure**: Agents that run autonomously, in parallel, and across environments (terminal, Slack, GitHub, Jira, cloud)
- **Massive adoption**: Trusted by over half the Fortune 500 and millions of developers — strong network effects and brand lock-in

## Strategic Focus
- **Scaling agentic capabilities**: Moving from assisted coding to fully autonomous software development agents
- **Enterprise expansion**: Building admin controls, SSO, compliance features, and usage analytics for large organizations
- **Platform ecosystem**: Expanding into adjacent tools (Jira, Slack, GitHub, mobile) to embed agents everywhere developers work
- **Model research**: Continued investment in training frontier coding models with reinforcement learning and synthetic data
- **Post-acquisition integration with xAI**: Leveraging SpaceX/xAI compute and infrastructure for even larger models

## Why Work Here
- **Mission-driven research environment**: Cursor describes itself as "an applied research team focused on building the future of software development" — a rare blend of R&D and product engineering
- **Talent density**: The company "obsesses over talent to an unusual degree" and designs itself as "a haven for self-motivated individual contributors"
- **Rapid growth trajectory**: From 0 to $3B ARR in ~4 years — employees work on products used by millions and see massive scale
- **Compensation**: Competitive for AI/engineering talent; top-of-market salaries and equity in a high-valuation private company
- **Work policy**: Mix of in-office (San Francisco, New York) and remote roles; many engineering roles are on-site
- **Engineering culture**: Two-day on-site final interviews with the core team; no AI tools allowed in first-round coding interviews — they value raw problem-solving
- **Team composition**: 579 employees with strong talent density from Stripe, Figma, Notion, Vercel, Graphite, Slack, Rubrik, and Plaid
- **Recent departures to**: Anthropic, OpenAI, Google, AWS — alumni are highly sought after

## Sources
1. [cursor.com](https://cursor.com)
2. [cursor.com/careers](https://cursor.com/careers)
3. [LinkedIn](https://www.linkedin.com/company/cursorai)
4. [Wikipedia](https://en.wikipedia.org/wiki/Cursor_(company))
5. [JobsByCulture](https://jobsbyculture.com/blog/working-at-cursor-2026)

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