Infrastructure Security Engineer

The role

An Infrastructure Security Engineer will design and secure core systems powering the platform. This role focuses on building security into infrastructure including container isolation, orchestration, identity, and secrets management in a multi-tenant, cloud-native environment.

What you will do

• Design and improve isolation mechanisms for multi-tenant workloads
• Strengthen boundaries between customers, workloads, and internal systems
• Identify and mitigate risks in distributed, dynamic compute environments
• Secure and harden containerized workloads and orchestration systems
• Improve workload isolation, scheduling boundaries, and runtime protections
• Evaluate tradeoffs in multi-tenant execution models
• Design and improve authentication and authorization systems across services
• Implement strong service-to-service identity and least-privilege access patterns
• Improve access controls across infrastructure and internal systems
• Build and maintain systems for securely managing secrets, tokens, and credentials

Required qualifications

• Experience securing cloud-native infrastructure and distributed systems in production
• Background in infrastructure, backend, or security engineering
• Experience in multi-tenant or high-scale environments
• Strong understanding of containerization and orchestration systems (e.g., Kubernetes or similar)
• Experience designing or securing isolation mechanisms in multi-tenant systems
• Solid understanding of authentication, authorization, and service identity models
• Experience with secrets management and secure handling of credentials
• Strong foundation in networking concepts (segmentation, service communication, access boundaries)
• Builder mentality to design and implement
• Pragmatic approach to security in fast-moving environments
• Comfortable working deeply with engineers and influencing system design

Nice to have

• Experience with sandboxing or runtime isolation technologies (e.g., gVisor, Firecracker, seccomp, or similar)
• Familiarity with kernel-level or low-level isolation primitives
• Experience securing Kubernetes or similar orchestration systems in production
• Background in developer infrastructure, compute platforms, or multi-tenant systems

About the company

Modal is building a new infrastructure layer for AI. The company has passed $1B in annualized run rate.