Infrastructure Security Engineer

Antithesis is growing and seeking an experienced Infrastructure & Security Engineer to join our Platform team, which owns the infrastructure, services and tools used to build, deploy and operate the Antithesis services & products. We strive to act as a productivity accelerator by providing secure, scalable infrastructure primitives that enable engineering teams to move fast without compromising security or reliability.

In this role, you will design, build, and scale secure cloud infrastructure that powers Antithesis' core systems and customer environments. You'll operate at the intersection of infrastructure, security, and reliability-ensuring our cloud environments are resilient, isolated, observable, and secure by default.

As our systems grow in complexity and scale, the security and isolation of our cloud infrastructure become increasingly critical. You'll help define and implement the technical foundations that protect our systems, customers, and data.

- Design, build, and operate secure, scalable cloud infrastructure across compute, networking, and storage

- Architect multi-tenant and isolated cloud environments with strong security boundaries

- Lead capacity planning and scaling initiatives to support rapid product and customer growth

- Make critical architectural decisions balancing performance, cost, reliability, and security

- Design and implement network segmentation, private networking, and zero-trust principles

- Build and maintain secure VPC architectures, ingress/egress controls, and service-to-service communication policies

- Implement tenant isolation strategies across infrastructure and workloads

- Conduct threat modeling and proactively reduce infrastructure attack surface

- Build and maintain authentication and authorization frameworks across internal systems

- Implement audit logging, access monitoring, and compliance-aligned controls

- Manage secrets, key management systems, and secure credential workflows

- Establish infrastructure-as-code standards and automation best practices

- Build tooling and paved paths that improve developer productivity and security posture

- Contribute to long-term infrastructure roadmap and technical strategy

- Mentor engineers on infrastructure and security best practices

We're looking for engineers who thrive at the intersection of cloud infrastructure, security engineering, and distributed systems .

- 5+ years of experience in infrastructure, platform, or security engineering

- Deep experience with cloud providers (AWS, GCP, or Azure)

- Strong knowledge of cloud networking concepts (VPCs, subnets, routing, firewalls, load balancing)

- Experience implementing IAM, RBAC, and least-privilege access models at scale

- Hands-on experience with Infrastructure-as-Code tools (Terraform, Pulumi, CloudFormation, etc.)

- Experience designing highly available, fault-tolerant systems

- Understanding of security best practices across cloud infrastructure

- Experience in high-growth or multi-tenant SaaS environments

- Background in security engineering or compliance frameworks (SOC 2, ISO 27001, etc.)

- Experience with secrets management, KMS, or certificate management

- Experience implementing monitoring and observability systems

Our team spans CS degrees, philosophy, mathematics, and everything in between, or nothing formal at all. What everyone shares is a high bar for engineering quality. We work in-person because it's how we build trust and tackle hard problems together.

Location: This position is in office in Vienna, VA.