Platform Security Engineer

We are hiring our founding Platform Engineer, Security to design, build, and operate the security infrastructure that powers Decagon's AI platform. This is a builder's role: you'll spend your time creating durable, well-engineered systems including paved paths for secure service creation, security tooling that automatically applies secure configurations, and infrastructure-as-code that makes it easy for every engineer at Decagon to do the right thing. As the first dedicated engineer at this intersection, you'll have outsized impact on how security infrastructure is built here, and you'll shape the technical direction of the infrastructure security program. You'll also help us invest in automation, observability, and self-service so the team operates with confidence. The work is close to the business. Decagon serves some of the world's most security-conscious enterprises, including major financial-services institutions, and the security platform you build directly unlocks these high-value deals. This role offers a clear runway to grow your impact across security, infrastructure, and platform engineering. In this role, you will design and implement secure, multi-tenant infrastructure that isolates customer data while enabling efficient AI model serving across our platform; Build golden paths for security including service templates, libraries, terraform policies, and automation; Own infrastructure-as-code (Terraform) and GitOps best practices; Expand and help operate the platforms behind alerting detection, secrets management, IAM, and automated remediation; Partner with Security, Infrastructure, and product engineering teams to translate enterprise and compliance requirements (SOC 2, ISO 27001, GDPR) into reliable, automated technical controls; Participate in security on-call and raise the bar on operability and incident learnings. Your background looks something like this: 5+ years building and operating production infrastructure with exposure to security; Deep knowledge of GCP and/or AWS; Proficiency with IaC; Strong coding in Python/Go/TypeScript; Experience with AI-assisted tooling; Experience with secure container deployment and Kubernetes security; Observability and incident-response tooling; Clear written communication.