Principal Security & Trust Engineer (AI‑SaaS)

Checkbox; Sydney; Hybrid; AUD 180,000 - 260,000; Full time

Benefits offered by this job

Hybrid working in Sydney CBD office

Competitive salary and equity

Learning and development budget

Flexible leave policy

Company hub with snacks and socials

Job summary

Checkbox, a Sydney-based AI-first SaaS start-up, is seeking a hands-on Principal Security Engineer to own application, cloud and infrastructure security, SIEM, vulnerability management and customer trust initiatives.

You will work across Product, Engineering, Platform, Identity, IT and Legal to embed security into design, build, deploy and operate software, while shaping guardrails for safe AI usage across the company.

Qualifications

• Strong experience in application security, infrastructure security, cloud security or security engineering roles.
• Experience securing modern SaaS web applications, APIs and cloud-based platforms.
• Strong AWS experience, with knowledge of Kubernetes and containerisation.
• Experience with SIEM ownership, detection engineering or incident response.
• Experience leading vulnerability management and remediation programs.
• Knowledge of SAST/DAST and secure SDLC practices.
• Experience with audits and compliance programs (SOC 2, ISO 27001/27017/27018).
• Ability to read, write, and ship practical security improvements.

Responsibilities

• Lead application security and infrastructure security practices across Checkbox, including secure development and API security.
• Own the company SIEM from detection through response and continuous improvement.
• Lead vulnerability management from detection to remediation and coordinate tests.
• Evaluate and optimize security tooling to support secure engineering at scale.
• Lead compliance audits and certifications (SOC 2, ISO standards).
• Maintain security policies, evidence, controls and audit documentation.
• Be the point of contact for customer security inquiries and reviews.
• Build AI security guardrails for internal teams using AI tools.

Skills

Application security

Infrastructure security

Cloud security

SIEM ownership

Vulnerability management

Security engineering

Go/TypeScript programming

Scripting (Bash)

Tools

Terraform

OpenTofu

CloudFormation

GitHub Actions

Job description

Checkbox, a Sydney-based AI-first SaaS start-up, is seeking a hands-on Principal Security Engineer to own application, cloud and infrastructure security, SIEM, vulnerability management and customer trust initiatives.

You will work across Product, Engineering, Platform, Identity, IT and Legal to embed security into design, build, deploy and operate software, while shaping guardrails for safe AI usage across the company.