Sr Platform Security Engineer (Zero Trust and Platform Security)

Greenhouse Software, Inc.; United States; Remote; USD 135,000 - 214,000; Full time

Job summary

Radian Arc is seeking a Sr Platform Security Engineer to design and implement security across the GPU cloud platform, emphasizing zero-trust and platform security for multi-tenant workloads. You will drive IAM, network security, automation, and AI-assisted security operations to safeguard deployments.

You will collaborate with infrastructure teams to embed security into deployment practices, improve detection, and enable secure-by-design infrastructure at scale.

Qualifications

• 7+ years of experience in cloud security or infrastructure security engineering.
• Experience securing large-scale distributed infrastructure platforms.
• Strong understanding of security architecture in cloud environments.
• Experience securing Kubernetes and containerized platforms.
• Familiarity with multi-tenant infrastructure security models.
• Experience with SIEM platforms and security telemetry.
• Ability to triage vulnerabilities and investigate incidents.
• Experience building security automation workflows.

Responsibilities

• Design and implement zero-trust security architecture across the platform.
• Implement identity-aware access controls for infrastructure, services, and operators.
• Enforce least-privilege access models for both internal teams and customers.
• Secure access paths to infrastructure components including control planes, orchestration systems, management networks, and operational tooling.
• Design and operate secure authentication and authorization systems.
• Provide IAM capabilities for multi-tenant environments.
• Integrate identity systems with infrastructure and platform components.
• Secure the underlying infrastructure used by GPU cloud platforms, including storage systems and networking fabrics.
• Design and implement security controls for large-scale distributed infrastructure networks.
• Develop automation workflows that improve detection, response, and remediation.
• Build integrations between security systems and operational tooling.
• Automate vulnerability triage, remediation workflows, and incident response processes.
• Contribute to SOAR-style automation systems coordinating security operations across the platform.
• Improve detection coverage and response automation across the platform.
• Design and maintain patch management strategies across the platform infrastructure.
• Track vulnerabilities and coordinate remediation across engineering teams.
• Maintain vulnerability remediation workflows and reporting for security posture visibility.

Skills

Cloud security

Zero-trust architecture

Security automation

Incident response

Team collaboration

Tools

HashiCorp Vault

HashiCorp Boundary

Tailscale

PKI systems

IAM systems (Authentik/KeyCloak)

Kubernetes security

Job description

Sr Platform Security Engineer (Zero Trust and Platform Security)

Europe

Start: ASAP

Type of Contract: Full-time (permanent or freeelance)

About Radian Arc

We’re specialists in outcome-optimized AI infrastructure - deploying, orchestrating and monetizing GPU compute where data, users and demand actually meet: inside telco networks, at the edge, and in core data centers.Not a generic AI platform. Not a consultancy. We’re the bridge between raw silicon and real-world results.

What impact you will have

Design and implement key security capabilities for the GPU cloud platform, ensuring that infrastructure, control planes, and multi-tenant workloads operate within a robust zero-trust security model.

This role focuses on securing the platform across identity, networking, infrastructure, platform, and automation layers while enabling high-performance AI workloads to run safely in multi-tenant environments.

As a Senior Platform Security Engineer, you will build security capabilities that integrate deeply with the platform, infrastructure stack, and operational tooling, enabling secure-by-design infrastructure at scale. You will also leverage automation and AI-assisted tooling to improve detection, triage, and response across the platform security stack.

What you’ll do

Zero Trust Architecture

• Design and implement zero-trust security architecture across the platform.
• Implement identity-aware access controls for infrastructure, services, and operators.
• Enforce least-privilege access models for both internal teams and customers.
• Secure access paths to infrastructure components including:
• Control planes,
• Orchestration systems,
• Management networks,
• Operational tooling.

Identity & Access Management

• Design and operate secure authentication and authorization systems.
• Implement IAM capabilities for multi-tenant environments in collaboration with platform and infrastructure teams.
• Integrate identity systems with infrastructure and platform components.
• Manage cryptographic infrastructure including:
• PKI systems,
• Key management,

Infrastructure & Platform Security

• Secure the underlying infrastructure used by the GPU cloud platform, including:
• Storage systems,
• Networking fabrics.
• Collaborate with infrastructure teams to ensure security is embedded in platform architecture and deployment practices.
• Contribute to security guardrails and secure deployment patterns for new infrastructure.

Network Security

• Design and implement security controls for large-scale distributed infrastructure networks.
• Implement secure segmentation and tenant isolation mechanisms using technologies such as:
• EVPN / VXLAN,
• VRF isolation,
• Encrypted transport,
• Zero-trust networking.
• Work with networking teams to secure high-performance fabrics including RDMA and InfiniBand environments.

Security Automation

• Develop automation workflows that improve detection, response, and remediation.
• Build integrations between security systems and operational tooling.
• Automate vulnerability triage, remediation workflows, and incident response processes.
• Contribute to SOAR-style automation systems that coordinate security operations across the platform.
• Support security monitoring and detection systems.
• Investigate and triage security alerts and potential vulnerabilities.
• Participate in incident response and post-incident analysis.
• Improve detection coverage and response automation across the platform.

Vulnerability & Patch Management

• Design and maintain patch management strategies across the platform infrastructure, including:
• Operating systems,
• Build automation pipelines that validate and deploy security updates across large infrastructure fleets.
• Track vulnerabilities and coordinate remediation across engineering teams.
• Maintain vulnerability remediation workflows and reporting for security posture visibility.

Security Telemetry & Detection

• Build and maintain security monitoring pipelines that ingest signals from infrastructure, networking, and platform components.
• Improve signal quality from SIEM platforms by developing correlation rules, enrichment pipelines, and automated triage workflows.
• Integrate security telemetry with platform observability systems to provide a unified view of infrastructure health and security posture.

AI-Assisted Security Operations

• Design and implement AI-assisted security workflows that analyze security telemetry and incident signals.
• Develop AI agents that help:
• Summarize security alerts,
• Correlate events across systems,
• Detect anomaly patterns,
• Use machine learning or LLM-based tooling to reduce alert fatigue and accelerate incident triage.

Compliance & Security Governance

• Help ensure platform security controls meet customer and regulatory requirements.
• Contribute to security policies and operational procedures.
• Help define measurable security metrics and compliance validation processes.

Technical Stack

Security Monitoring & Detection

• Snort IDS/IPS.
• TheHive.

Security Infrastructure

• HashiCorp Vault.
• HashiCorp Boundary.
• Tailscale.

Identity & Access

• PKI infrastructure.
• IAM systems such as Authentik/KeyCloak.
• Identity federation.

Secure Networking

• Zero-trust networking models.
• Encrypted network transport.
• Citrix NetScaler.

Platform Security

• Container runtime security.

Security Automation

• Python / Go.
• Security automation frameworks.

What you’ll need

Core Experience

• 7+ years of experience in cloud security or infrastructure security engineering.
• Experience securing large-scale distributed infrastructure platforms.

Infrastructure Security

• Strong understanding of security architecture in cloud environments.
• Experience securing Kubernetes and containerized platforms.
• Familiarity with multi-tenant infrastructure security models.

Identity & Cryptography

• Experience implementing identity and access management systems.
• Strong understanding of PKI, key management, and secure authentication systems.

Network Security

• Understanding of datacenter networking security concepts.
• Familiarity with segmentation, tenant isolation, and zero-trust networking.

Security Operations

• Experience with SIEM platforms and security telemetry.
• Ability to triage vulnerabilities and investigate incidents.
• Experience building security automation workflows.

What we offer

Attractive compensation package reflecting your expertise and experience.

A great work environment characterised by friendliness, international diversity, flexibility, and a hybrid-friendly approach.

You’ll be part of a fast-growing scale-up with a mission to make a positive impact, offering an exciting career evolution.

Our job titles may span more than one job level. The actual base pay is dependent on a number of factors, such as transferable skills, work experience, business needs and market demands.

Our Inclusive Responsibility

Radian Arc is committed to creating a diverse and inclusive environment and is proud to be an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, veteran status, or any other protected category under applicable law.