Platform Security Engineer - Office of the CISO

Position Overview: We’re looking for an experienced Platform Security Engineer to join the CISO team and help drive our product security to the next level and beyond. The ideal candidate for the role will be a highly technical, passionate, team-oriented professional who can evolve our security infrastructure and platform security, embedding secure practices into every layer of our product platform and operations. In this strategic and hands-on role, you will architect, implement, and scale robust security automation, policy enforcement, and threat detection systems across our CI/CD pipelines, data pipelines, and cloud infrastructure and environments. You’ll be instrumental in shaping how security is integrated into software development and operations, driving security visibility, reliability, and trust at global scale.

The ideal person for this role must be mission and values-driven, must have an ownership mentality, and must put the well-being of our customers, our teammates, and our organization at the forefront of how they operate. This person must be able to operate and thrive in a dynamic, high-growth startup environment within an established Cybersecurity, GRC, and IT team and programs. This is a critical, high-impact role that will serve as a catalyst for growth for any seasoned cybersecurity professional.

The Platform Security Engineer will be responsible for developing, implementing, optimizing, scaling, automating, and operating effective security controls and capabilities within the organization and product suite. The Platform Security Engineer works closely with DevOps and Engineering teams to support the company's security needs, provide support, and facilitate secure technology operations.

Candidates applying for this sensitive and high-impact role should be highly technical team players with software engineering, automation, and application and infrastructure security experience, capable of implementing protection, detection, and response capabilities and industry best practices across an organization with a cybersecurity mission and modern tech stack. This is a multi-faceted role within a fast-moving startup and will require the successful candidate to possess an ownership mentality, sound judgment, personal responsibility, and initiative.

In this role, you will support the company’s overall security mission and help drive alignment, maturity, capacity, and optimization where needed. 

Your Responsibilities Will Include

1. Security Architecture and Technical Leadership

• Design and drive a holistic Platform Security strategy aligned with business risk posture and compliance requirements.
• Collaborate with IT, GRC, DevOps, and Engineering teams to build secure and privacy-by-default product hosting platforms.
• Define and implement secure patterns for cloud-native architectures (e.g., containers, serverless, IaC).
• Create automation workflows for security incident detection and response across environments.
• Establish continuous compliance pipelines for standards like SOC 2, ISO 27001, FedRAMP, or HIPAA.
• Lead security architecture reviews, threat modeling sessions, and secure coding workshops.
• Mentor more junior security engineers and influence cross-functional teams through technical thought leadership.

2. Ensuring the Obsidian product is built and deployed to a high-security standard

• Ensure that application code, images, dependencies, and infrastructure are scanned for vulnerabilities and that vulnerabilities are remediated in a risk-informed and timely manner.
• Embed security controls into build and deployment pipelines (GitLab CI).
• Mature vulnerability scanning (SAST, DAST, SCA) and integrate results into feedback loops for security and engineering teams.
• Develop and enforce guardrails and policy-as-code (OPA) to prevent misconfigurations and policy drift.
• Ensure that CI/CD infrastructure and other critical infrastructures and systems are hardened according to security best practices and standards, and monitored for security threats.
• Harden Kubernetes clusters, container runtimes, and cloud environments (AWS/GCP) using security standards and best practices.
• Lead implementation of infrastructure as code (Terraform), security validation, and drift detection.
• Drive zero-trust principles in service-to-service communication and access control.
• Support product penetration testing and corporate red teaming exercises.

3. Ensuring Obsidian assets are managed to a high-security standard

• Implement security tooling, automation, and orchestration as needed for detection, response, reporting, and vulnerability management capabilities.
• Ensure that security tooling is maintained, optimized, and consistently deployed across the Obsidian install base.
• Develop security threat-detection rules and analytics within Obsidian security tooling systems, and drive security posture maturity.
• Support security program continuity and resiliency by maturing security documentation, processes, and runbooks. Build playbooks for recurring security events and operations.

What are we looking for?

• A person who is excited about working at an industry-leading cybersecurity startup company with enterprise security needs.
• 8+ years of engineering, infrastructure or security experience. Level commensurate with experience
• Proficient in software engineering with emphasis on the Python programming language at a minimum
• Proficient in Terraform Infrastructure-as-Code
• Proficient in securing Kubernetes
• Proficient in securing AWS and GCP environments
• Proficient in securing the GitLab platform
• Proficient in security automation
• Excellent understanding of multiple security domains, such as protection, detection, response, application security, vulnerability management, or threat intelligence
• Be obsessive about security while doing everything possible to support the overall mission.
• Experience working with multiple internal and external stakeholders during incident lifecycles
• Experience communicating across a company to encourage and educate on best practices, standards, and policies

What we can do for you

• Be part of a team-first, low-ego, mission-focused culture.
• Provide opportunities for professional development.
• Provide opportunities to make high-impact contributions to security.
• Influence the Obsidian product development.
• Annual conference attendance budget
• Competitive salary, equity, and health benefits
• Opportunity to publish research, share non-proprietary code, and present at conferences
• Reserve your seat on our rocket ship! We are funded by Greylock Partners, Google Ventures, Menlo Ventures, WingVC, Norwest Venture Partners, and are growing fast.

This role is a game-changer, focused on securing our company and product as we provide cutting-edge capabilities to help organizations enhance their security.