Senior Engineering Manager, Clients Team

Horizon3

2d•$242,250 - $275,000•Remote

About The Position

Horizon3.ai is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find, fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZero™ 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 IT Ops/SecOps teams, consulting pentesters, and MSSPs and MSPs. We are a fusion of former U.S. Special Operations cyber operators, startup engineers & operators, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools and 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. As a remote first company, we require minimum 25Mbps consumer grade broadband connection.

Requirements

Demonstrated expertise leading teams that design, build, and operate containerized software (Docker, VM images) deployed into on-premise or customer-managed environments.
Experience implementing robust software supply chain practices — secure builds, image signing (cosign, Notary), reproducible builds, and vulnerability scanning in CI.
Experience designing and operating OTA update mechanisms for distributed agents or edge software at scale — including staged rollouts, rollback, and delivery verification.
Ability to reason about correctness in opaque, customer-controlled environments where you cannot observe failure modes directly.
Experience building or significantly growing an engineering team — including hiring, onboarding, and establishing engineering norms tailored for shipped software.
Proven ability to define and instill engineering culture: rigorous code review standards, robust testing across diverse customer environments, and a strong culture of ownership.
Drives high-impact architecture decisions rigorously — requires design documents, runs structured reviews, builds consensus, and ensures decisions account for customer environment variables.
Proficient in Go (preferred), Python, or C++.
Strong Linux OS-level operations: container runtimes, networking in corporate environments, systemd, process isolation.
Experience with CI/CD pipelines for building and signing container images (cosign, Notary v2, or equivalent).
Familiarity with OTA update protocols and frameworks: TUF (The Update Framework), Omaha, or custom mechanisms.
Understanding of TLS, certificate pinning, and secure software delivery in hostile network environments.

Nice To Haves

Exposure to cybersecurity, pentesting tools, or vulnerability remediation.
Experience with cross-platform agents (Windows/Linux) and endpoint telemetry.
Background in software running in air-gapped or restricted network environments.
Familiarity with SLSA supply chain security framework.

Responsibilities

Build, mentor, and grow Client Platform to ~10 engineers across Image Build & Release and OTA Services.
Directly manage the Engineering Managers of both sub-teams and set the technical and cultural direction for the full org.
Establish engineering norms and a culture of ownership for a team whose software runs in environments you cannot control.
Lead end-to-end CI/CD workflows to create, sign, and reliably publish the NodeZero runner container image.
Own software supply chain security: reproducible builds, image signing, SBOM generation, and vulnerability scanning in CI.
Architect and operate the over-the-air update delivery system that keeps NodeZero runners current across thousands of customer environments — reliably, securely, and without requiring manual customer IT intervention.
Collaborate closely with Security Research to ensure the runner seamlessly executes new autonomous pentest capabilities as they ship.
Act as a Product Owner: Partner with product managers, security researchers, and customer success to manage the client-side roadmap.