Senior Attack Engineer, Kubernetes

📋 Job Overview

Horizon3 is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find and fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZeroTM platform, delivers production-safe autonomous pentests and other key assessment operations that scale across the largest internal, external, cloud, and hybrid cloud environments. NodeZero has been adopted by organizations of all sizes, from small educational institutions to government agencies and Global 100 enterprises. It is used by ITOps/SecOps teams, consulting pentesters, and MSSPs and MSPs. We are a fusion of former U.S. Special Operations cyber operators, startup engineers, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools, false positives resulting in alert fatigue, blind spots, \"checkbox” security culture, cybersecurity skills shortage, and the long lead time and expense of hiring outside consultants. Collectively, we are a team of learn it alls, committed to a culture of respect, collaboration, ownership, and results.

🏢 About Horizon3

Horizon3 is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find and fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZeroTM platform, delivers production-safe autonomous pentests and other key assessment operations that scale across the largest internal, external, cloud, and hybrid cloud environments. NodeZero has been adopted by organizations of all sizes, from small educational institutions to government agencies and Global 100 enterprises. It is used by ITOps/SecOps teams, consulting pentesters, and MSSPs and MSPs. We are a fusion of former U.S. Special Operations cyber operators, startup engineers, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools, false positives resulting in alert fatigue, blind spots, \"checkbox” security culture, cybersecurity skills shortage, and the long lead time and expense of hiring outside consultants. Collectively, we are a team of learn it alls, committed to a culture of respect, collaboration, ownership, and results.

🎯 The Role

We’re looking for a senior offensive security engineer to lead the development of Kubernetes attack capabilities in NodeZero. You’ll research how attackers move from a compromised workload or identity through and beyond a cluster, and turn that research into safe, repeatable capabilities. You’ll own complex work from attack research and technical design through integration and customer-facing proof, while helping set the direction for Kubernetes coverage across cloud and self-managed environments. This is not a maintenance role. You'll serve as the technical lead helping define Horizon3's Kubernetes offensive security strategy and will have a first-hand influence on how Kubernetes attacks are integrated into the platform.

✅ Key Responsibilities

• Lead offensive security research into Kubernetes clusters, workloads, identities, configurations, and cloud-connected environments.
• Design and build production-quality Python attack capabilities that model realistic attacker perspectives, including an assumed-breach foothold in a pod or workload.
• Develop and validate attack paths involving Kubernetes RBAC, service accounts and credentials, workloads and pods, secrets, cluster and node boundaries, network reachability, and integrations with cloud identities and managed Kubernetes services.
• Assess Kubernetes security weaknesses and determine whether they create meaningful, provable impact; build safe validation and negative testing into the capability.
• Own technical planning for substantial Kubernetes initiatives: identify coverage gaps, prioritize research, make design trade-offs, and coordinate delivery with Product, platform, and engineering partners.
• Integrate attack content into NodeZero’s execution and results flows so customers receive reliable evidence and clear explanations of the paths found.
• Review code and designs, establish quality expectations, mentor teammates, and share Kubernetes offensive-security expertise across the team.
• Document methodologies, assumptions, limitations, and test approaches; contribute to internal and external technical enablement where appropriate.

📌 Required Qualifications

• Deep hands-on experience with Kubernetes security and offensive testing of containerized environments.
• Expert level understanding of Kubernetes architecture and identity and authorization controls, especially RBAC, service accounts, workloads, and cluster boundaries.
• Strong Python engineering skills and experience productizing security research into reliable automation.
• Experience with penetration testing, red teaming, vulnerability research, container security, or offensive security tooling.
• Ability to lead ambiguous, cross-functional technical work and communicate attack paths and impact clearly.
• A strong safety and product mindset: you can distinguish a theoretical weakness from a reproducible, actionable finding and build capabilities that behave predictably.
• A record of owning complex technical projects, making sound trade-offs, and communicating clearly with technical and non-technical partners.
• Strong written communication and a habit of documenting research and design decisions.

⭐ Desirable Experience

• Experience with EKS, GKE, AKS, OKE, or other managed Kubernetes services.
• Knowledge of Linux, containers, cloud workload identity, Kubernetes operators, Helm, or infrastructure as code.
• Experience with network attack paths, container escape research, or cloud-to-cluster attack paths.
• Contributions to open-source security tooling, public research, conference talks, or vulnerability disclosure.

🎁 Benefits

Inclusive Team: We value diversity and promote an inclusive culture where everyone can thrive.
Growth Opportunities: Be part of a dynamic and growing team with numerous career development opportunities.
Innovative Culture: Work in a collaborative environment that encourages creativity and out-of-the-box thinking.
Hybrid & Remote Work: We embrace a mix of remote and hybrid work models depending on role and location, including our Chicago office, where some roles require regular in-office presence.
Competitive Compensation: We offer competitive salary, equity and benefits. Our benefits include health, vision & dental insurance for you and your family, a flexible vacation policy, and generous parental leave.

🛂 Visa & Eligibility

We are a fully remote company, and this job may require up to 10% of travel to be successful.