AWS Cloud Security Engineer

About the company

On.Energy is a Miami-headquartered independent power producer that develops, integrates and operates AI-driven battery energy storage systems across the Americas.

About this role

<div class="content-intro"><p>ON.energy<span class="Apple-converted-space">&nbsp;</span>is building the backbone of energy and AI infrastructure powering grid-safe data centers and mission-critical facilities. The company supplies and operates hyperscale power systems that solve the toughest resilience challenges, delivering custom solutions for AI data centers, mission-critical facilities, and front-of-the-meter assets. ON recently announced a 5GW partnership, with 3GW currently under construction across multiple hyperscale data center campuses. With patented technology and proprietary software,<span class="Apple-converted-space">&nbsp;</span>ON.energy<span class="Apple-converted-space">&nbsp;</span>develops projects worldwide that set new benchmarks for resilience.</p></div><h3><strong>Key Responsibilities&nbsp;</strong></h3> <ul> <li>The multi-account security foundation. AWS Organizations structure, SCPs, guardrails, a security tooling account, centralized logging, and secure baselines — delivered as infrastructure as code, not console clicks.</li> <li>Security standards and review gates. You can mandate controls and block deploys that introduce unacceptable risk, through review gates on identity and network changes, a documented exception path, and a defined escalation route.</li> <li>AWS identity and access. IAM Identity Center as the single front door, federated with Entra ID in partnership with IT, who own Entra as the source of truth. Role and group model mapping job functions to permissions; joiner/mover/leaver; privileged and break-glass access; workload identity; recurring access reviews. Hands-on at first, progressively automated so it stops being manual work.</li> <li>Cloud-to-site connectivity and segmentation — the defining part of this role. Every plant, BESS site, and remote asset that reaches our cloud does so over a path you design and defend: site-to-cloud VPN and private connectivity, hard segmentation between IT and OT zones, DMZ and broker patterns for site telemetry, certificate and device identity for field gateways, remote vendor access to sites, and strict control over what may initiate traffic in each direction. You own the cloud side of that boundary and share the path itself with the OT security owner.</li> <li>Threat detection, monitoring, and mitigation. You are expected to know how attacks actually run — credential and token abuse, cross-account privilege escalation, exposed control and management interfaces, lateral movement from a compromised site network into cloud, supply-chain and dependency compromise, ransomware staging — and to build the monitoring that catches them. GuardDuty, Security Hub, Detective, Inspector, Config, and CloudTrail tuned for real signal-to-noise, detections mapped to MITRE ATT&amp;CK and ATT&amp;CK for ICS, runbooks the wider team can execute, and the mitigations driven to done.</li> <li>Vulnerability management. Scanning coverage across workloads, images, and dependencies; risk-based triage and prioritization; remediation SLAs and exception handling; posture reporting. You identify and prioritize; the AWS engineers remediate in the workloads they own.</li> </ul> <p>&nbsp;</p> <h3><strong>Key Requirements</strong></h3> <ul> <li>5+ years in cloud security, security-focused infrastructure, or cloud operations, with deep hands-on AWS.</li> <li>Production experience in multi-account AWS environments.</li> <li>Demonstrable command of attacker techniques and the detections and mitigations that counter them — you can walk an intrusion path end to end and explain how you would catch it, contain it, and close it.</li> <li>Hybrid and site-to-cloud network security: segmentation, VPN, private connectivity, firewalls, routing, DNS, CIDR and subnetting — securing connections between cloud and physical facilities.</li> <li>Strong AWS identity: roles, policies, permission sets, MFA, least privilege, access reviews; IAM Identity Center federated with an external IdP, ideally Microsoft Entra ID.</li> <li>AWS-native security services: GuardDuty, Detective, Security Hub, Inspector, Config, CloudTrail, KMS, WAF.</li> <li>Infrastructure as code — CDK, CloudFormation, or Terraform. You build controls, you don't click them.</li> <li>Advanced English (B2–C1) for daily work with English-speaking teams and written security documentation.</li> </ul> <h3><strong>Preferred Qualifications</strong></h3> <ul> <li>Security experience in OT- or ICS-adjacent environments: IT/OT segmentation, Purdue-model zoning, secure remote access to field sites, and protocols such as Modbus, DNP3, OPC UA, or MQTT crossing into cloud.</li> <li>Detection engineering and SIEM work; threat modelling; incident response you have personally run.</li> <li>Regulated or compliance-driven environments where access control, monitoring, and audit evidence are held to an external standard.</li> <li>Turning scanner output and audit findings into prioritized, actionable work for engineers who do not report to you.</li> <li>Troubleshooting security, identity, networking, and infrastructure issues across cloud and hybrid environments.</li> <li>Landing zones, Control Tower, and security account patterns.</li> <li>IEC 62443 or NIST SP 800-82 familiarity.</li> <li>Containers and serverless workloads.</li> <li>Energy, utilities, or other mission-critical environments.</li> <li>Wazuh, Datadog, Grafana, or similar.</li> <li>Security documentation and ADRs.</li> </ul> <h3><strong>Certifications</strong></h3> <p>Valued as a signal, not a substitute for experience: AWS Certified Security – Specialty; AWS Certified Advanced Networking – Specialty; AWS Certified Solutions Architect; GICSP or GIAC GRID; CISSP; CCSP; Microsoft Certified: Identity and Access Administrator Associate.</p> <p>&nbsp;</p> <p>#LI-AD1</p><div class="content-conclusion"><hr> <p><strong>For US-based roles - What you’ll get:</strong></p> <ul> <li>Competitive salary + annual performance-based bonus eligibility</li> <li>Medical, dent