Application Security Engineer

Responsibilities

• Define, build, and operate application vulnerability identification capabilities, including tooling, triage workflows, and remediation techniques.
• Manage and mature the AppSec tooling stack, integrating static and dynamic security testing into developer workflows like GitHub and Slack.
• Own and mature the HackerOne bug bounty program by improving signal-to-noise ratios and strengthening researcher relationships.
• Lead threat modeling and security design reviews for new services, APIs, and mobile features.
• Build AI agents and automated workflows to triage vulnerability reports, validate exploits, and draft remediation pull requests.
• Partner with engineering teams to harden authentication, authorization, and input validation across GraphQL gateways and Kubernetes workloads.
• Develop offensive security capabilities, including internal security testing and red team exercises.

Requirements

• 5+ years of application security or software engineering experience with a strong security focus.
• Proficiency in at least one of the following languages: Python, Go, TypeScript, or Ruby.
• Hands-on expertise with security risk detection toolchains, such as GitHub Advanced Security or Semgrep.
• Strong understanding of application and API security vulnerabilities, including GraphQL, REST, and gRPC.
• Practical threat modeling skills and experience with cloud/container security (AWS and Kubernetes).
• A mindset focused on using AI and automation to eliminate manual security work.

Preferred Qualifications

• Experience with offensive security, including pentesting, API security, or red team operations.
• Experience running bug bounty or coordinated disclosure programs at scale.
• Experience securing AI/ML pipelines, agent frameworks, or MCP-style integrations.
• Mobile application security review experience (iOS and Android).
• Relevant offensive security certifications such as OSCP or OSWE.

About the Company

Opendoor is building the modern system of homeownership, providing an end-to-end online experience that gives people the freedom to buy and sell homes on their own terms. Our mission is to tilt the world in favor of homeowners and those who aim to become one.