Senior Engineering Manager, Site Reliability

Engineering Leader Opportunity

Horizon
3.ai 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.

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.

We are looking for an engineering leader to build and lead the Site Reliability function s leader is expected to hire a team and establish a Site Reliability function to define and drive investments in operational excellence to ensure Horizon3's product and service offerings meet customer and business expectations.

Establish an SRE function.

• Build a SRE team, from scratch. Hire experienced site reliability staff and build a team of 4-6 in year one.
• Professionalize incident management. Define and document incident processes and practices for your SRE team and for the application feature teams. Make tool and vendor decisions to support processes.
• Drive incident professionalism and reliability culture across the engineering organization through training and process adoption.

Drive Engineering Excellence

• Use design reviews, code reviews, and blameless retrospectives to drive a culture of quality and excellence in engineering.

People Leadership and Project Management

• Balance incident response while also executing on a roadmap of observability and reliability engineering initiatives.
• Hire and directly manage site reliability engineers.
• As a Manager, you will be responsible for:
• Recruiting and onboarding talented individuals to support our organizational goals
• Mentoring, coaching, equipping, and developing your team
• Recognizing and retaining high performers
• Leading horizontally with peer Management & Senior Leaders

Building and Leading SRE Teams

• Demonstrated experience leading hiring and growing SRE or Infrastructure teams. Experience leading or building SRE functions, including incident management processes, on-call programs, SLO/SLA definition, and operational runbooks.

• Previous career experience as a Site Reliability Engineer. Comfortable in being hands-on while you grow and hire your team.

• Deep hands on experience with observability: application performance management, logs and traces, and golden signals and service-specific metrics.

• Experience in selecting and deploying incident management tooling (e.g., Pager Duty, Fire Hydrant, etc.) and creating decision making frameworks for vendor selection.

• Strong working knowledge of at least one major cloud provider (AWS, GCP, or Azure) — infrastructure, networking, managed services, IAM, cost management. AWS preferred.

Engineering Culture and Process

• Experience in design practices like architecture decision records or RFCs in the infrastructure or platform engineering context.

• Able to write clear, durable process documentation that engineering teams can adopt.

• Experience in providing education and training on runbook development, on-call expectations, incident investigations, and running effective postmortems.

• Ability to engage with Product and Engineering leaders to define SLOs and drive culture of ownership across teams.

Leadership and People Management

• Proven ability to hire, develop, and retain high-performing engineers and engineering managers in remote or distributed environments.

• Proven skills in managing a backlog of strategic roadmap initiatives and a competing stream of operational needs against capacity constraints.

• Strong communication skills across technical and non-technical audiences.

• Proven ability to build, scale, and retain high performing engineering teams in remote or distributed environments.

Occasional Business Travel Required

This position is remote, but this job may require up to 10% of travel to be successful.

Perks of Horizon
3.ai

• 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…