Senior Platform Security Engineer

Gemini•San Francisco, NY

2d•$140,000 - $200,000•Hybrid

About The Position

The Platform Security team secures Gemini's infrastructure through service hardening and by developing and supporting a suite of foundational tools. As a Senior Platform Security Engineer, you will build and maintain security controls across diverse environments—from hardening cloud and container orchestration systems to enhancing our non-cloud infrastructure. This is a hands-on engineering role where you'll write production code daily, not just configuration. You'll own security initiatives from design through production operations. This role requires strong software development skills, practical experience with AWS and Kubernetes security, and the ability to partner with engineering teams to enable secure delivery. You will also apply expertise in critical neighboring areas, including PKI, core cryptography, identity management, and network security, to ensure comprehensive protection across the stack. This role is required to be in person twice a week at either our San Francisco, CA or New York City, NY office.

Requirements

5+ years of experience in Information Security, SRE, or Systems Engineering
Strong software development skills in Python or Go with experience building production services
Solid experience with AWS (or similar cloud providers), including familiarity with IAM roles, VPCs, and native security controls
Hands-on experience with Kubernetes/EKS and containerization concepts, including pod security policies and container lifecycle
Understanding of IAM principles, RBAC, and least-privilege access models
Proficiency in Terraform for infrastructure-as-code
Ability to self-scope and execute technical goals with minimal supervision

Nice To Haves

Experience with identity providers (IdP) like Okta and standards like SAML/OIDC
Experience writing Policy-as-Code (e.g., Open Policy Agent/Rego)
Background in Linux systems engineering or network security
Experience building and operating high-availability critical systems

Responsibilities

Build and maintain security controls for AWS and Kubernetes (EKS) environments, including guardrails, container security scanning, and infrastructure-as-code (Terraform) security
Support IAM initiatives by helping to design and maintain access controls, role-based access control (RBAC) models, and identity governance workflows
Design, deploy, and maintain internal security services and platforms that other engineering teams rely on
Act as a security partner to engineering teams, helping them make secure architecture decisions without blocking innovation
Work across functions—partnering with AppSec, Threat Detection, and GRC—to identify and reduce risk across the entire stack
Participate in on-call rotation for platform security incidents