Senior Platform Security Engineer – AI & Cloud

Sierra; San Francisco (CA); On-site; USD 170,000 - 250,000; Full time

Benefits offered by this job

Flexible PTO

Health benefits

Life insurance

Retirement plan

Parental leave

Fertility benefits

Snacks & coffee

Equity plans

Job summary

Sierra in San Francisco seeks a Security Leader to own the security of our platform, including applications, cloud, network, and AI agents. You will drive secure design reviews, threat modeling, and implement automation within CI/CD to speed up secure delivery.

You will work with engineering, product, and GRC to embed security across the SDLC, communicate risks, and champion best practices as we scale.

Qualifications

• Broad security expertise across web, cloud, and networking foundations.
• Hands-on programming, scripting, and DevOps tooling for automation.
• Familiar with secure coding, threat modeling, vulnerability scans, and incident response.
• Adaptable in a fast-paced startup, able to handle ambiguity gracefully.
• Strong written and verbal communication for cross-functional stakeholders.
• Customer-first mindset and curiosity about user needs.

Responsibilities

• Lead Security for Our Platform. Take charge of application, cloud, network, and AI agent security; perform secure design reviews and threat modeling.
• Collaborate with Cross-Functional Teams. Partner with engineering, product, and GRC to embed security in the SDLC and prioritize fixes.
• Implement Automation & Tooling. Integrate security tooling into CI/CD and use AI-based solutions for scans and compliance.
• Continuously Improve Security Posture. Audit cloud environments, review IAM, and drive best practices as the company scales.
• Enable Enterprise Customer Needs. Present security posture to enterprise clients and address regulated data concerns.

Skills

Web security

Cloud security

Networking

DevOps & automation

Threat modeling

Communication

Tools

Terraform

CloudFormation

CI/CD tooling

Vulnerability scanning

IAM governance

Job description

Sierra in San Francisco seeks a Security Leader to own the security of our platform, including applications, cloud, network, and AI agents. You will drive secure design reviews, threat modeling, and implement automation within CI/CD to speed up secure delivery.

You will work with engineering, product, and GRC to embed security across the SDLC, communicate risks, and champion best practices as we scale.