Your role

As a Security Engineer, you will own the security of the systems financial institutions trust with sensitive client data and regulated financial workflows: our applications, our cloud infrastructure and the engineering practices that produce them.

Saturn is a Series A, Y Combinator-backed company building the AI-native operating system for financial advice. Our platform combines a living data model of the client, AI agents that complete complex advice and operational workflows, and compliance logic embedded directly into how work is produced. That means real client data, real money movements and real regulatory consequences, all moving through systems that are still being built.

You will not operate as a gatekeeper or arrive at the end of a project to review it. You are expected to understand how systems actually work, identify where a failure or an attack would cause real harm, and help teams fix it at the right level. Your work is what allows Saturn to meet the security expectations of large financial institutions without slowing engineering down with process for its own sake.

The Team

Our engineers care deeply about craft, speed and quality. They include early and founding team members from companies including Rippling, Postman, Gojek, CRED and Slice.

You will work alongside product designers, backend engineers, AI engineers and domain experts with decades of experience in financial advice and compliance.

We are building a small, high calibre engineering organisation for people who want genuine ownership, difficult product problems and the opportunity to shape an important company while its foundations are still being formed.

What You’ll Work On

Application and API security across Saturn’s web applications, backend services and integrations, including authentication, authorisation, session management and firm-level data separation
AWS security, covering IAM, network controls, secrets, encryption and workload isolation
Threat modelling and security review for new systems, financial workflows, external integrations and AI capabilities, joining projects early enough to change their design
Vulnerability management end to end: discovery, prioritisation by real risk, remediation and verification across code, dependencies, cloud resources and employee systems
Security tooling and automation, including checks built into CI/CD, so the same work is never done manually twice
Detection and incident response, from logging and alerting through investigation and recovery, turning each incident into a lasting improvement to systems and controls
AI security, including prompt injection, unsafe tool execution, retrieved data and sensitive information disclosure
Evidence and assurance for SOC 2, enterprise security reviews and customer due diligence, plus the reusable security patterns engineering teams adopt as standard

What We’re Looking For

Security engineering experience. 3+ years in security engineering, software engineering, infrastructure security or a closely related role, with a track record of improving the security of production software or cloud infrastructure
Application and API security depth. Strong command of common web and API vulnerabilities including the OWASP Top 10, and practical knowledge of authentication, authorisation, sessions, secrets and encryption
Cloud security. Hands-on experience securing AWS or another major cloud platform, including IAM, network security and cloud-native controls
Secure design. You have run threat modelling and architecture reviews, and you recommend proportionate controls that fit the system and its stage rather than the textbook answer
You build, not just advise. You can write software and automation in Go, TypeScript, Python or a comparable language, and you integrate security checks into how engineers already work
Detection and response. Understanding of security logging, monitoring and incident investigation, and comfort owning a problem through investigation, remediation and verification
Risk judgement at startup pace. You start from the likely harm and attack path, separate material risk from low-value security work, and prioritise sensibly with incomplete information
Strong written communication. You describe risks and mitigations clearly enough that engineers, customers and leadership can act on them, and you document accepted risks rather than leaving them implicit

Preferred

Security engi

Security Engineer at Saturn