Senior Security Engineer, Platform Security

Block builds simple, powerful tools that make progress towards an economy that’s truly open to all. The Platform Security team is responsible for securing Block's cloud, compute, and network infrastructure across multiple business units including Square, Cash, and Afterpay, focusing on critical security risks and cloud security strategy.

Responsibilities:

• Architect and evolve cloud security guardrails. Design and implement SCPs, GCP org policies, and IAM controls that shape how Block uses cloud infrastructure for years to come
• Build automation to discover, measure, and contextualize security issues. Develop integrations with CSPM/DSPM tools and internal platforms to surface and prioritize findings
• Own the cloud security exception lifecycle. Build and maintain the tooling and processes that allow teams to request, review, and track security exceptions at scale
• Partner with platform teams to deliver solutions that permanently eliminate entire categories of cloud security risk
• Deliver key cloud security assurance functions. Balance the need to remediate critical misconfigurations and sensitive data exposures with being responsible stewards of our developers' time
• Develop risk-based prioritization. Build data pipelines and dashboards that aggregate security signals and help leadership understand posture trends
• Respond to and triage cloud security alerts. Support on-call rotations, investigate findings, and help engineers resolve issues quickly
• Produce quality software that stands the test of time and scales across Block's multi-cloud footprint
• Think, build and iterate in an AI-augmented environment

Requirements:

• 5+ years of experience as a software or security engineer
• 4+ years of experience securing infrastructure running on AWS and/or GCP at scale
• Deep experience with Infrastructure-as-Code. Terraform (including securing Terraform pipelines), SCPs, GCP org policies, and understanding of best practices and pitfalls when deploying guardrails at organizational scale
• Experience with cloud security posture management (CSPM) tools such as Wiz, and familiarity with DSPM concepts (sensitive data discovery, classification, and remediation)
• Strong understanding of IAM. AWS IAM policies, roles, SCPs, permission boundaries; GCP IAM, service accounts, and org-level constraints
• Experience maturing the cloud security posture of large, complex, multi-account/multi-project environments
• Demonstrated ability to successfully deliver complex, multi-faceted projects from concept to launch
• Demonstrated fluency with AI-assisted development tools (e.g., Claude Code, Cursor, GitHub Copilot, or similar agentic coding tools) in real production work
• Experience with Kubernetes security (pod security policies, network policies) in environments like EKS or GKE
• Familiarity with BI and data exploration tools like Looker and Snowflake for building security metrics and dashboards
• Experience building or operating security exception/risk acceptance workflows at scale
• Familiarity with cloud networking and network segmentation strategies
• Ability to work well cross-functionally and communicate with audiences who may not have a security or engineering background
• Experience supporting multi-business-unit organizations with varying compliance and regulatory requirements