Sr Platform Security Engineer

Location & work modality: Europe (remote)
Start: ASAP
Type of Contract: Full-time (permanent or freeelance)
About Radian Arc
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,
- Certificate lifecycle automation.
Infrastructure & Platform Security:
- Secure the underlying infrastructure used by the GPU cloud platform, including:
- Kubernetes clusters,
- Virtualization layers,
- 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.
Threat Detection & Incident Response:
- 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,
- Container runtimes,
- Kernel updates,
- Infrastructure components.
- 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,
- Assist operators during incident investigations.
- Use machine learning or LLM-based tooling to reduce alert fatigue and accelerate incident triage.
Compliance & Security Governance:
- Help ensure platf