Senior Customer Success Manager, EMEA in London

Horizon3.ai is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find and fix 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 various environments.

As a Customer Success Manager in EMEA, you will play a key role in scaling and strengthening our international post-sales experience. You will serve as a strategic advisor to a portfolio of high-value customers, partnering directly with technical and business stakeholders to drive adoption, value realization, retention, and growth.

This role requires a background in cybersecurity and someone who is consultative, proactive, and excited to build strong customer relationships across geographies. You’ll collaborate cross-functionally with Sales, Product, Engineering, and Support while helping shape and evolve the Customer Success experience across the EMEA region.

Responsibilities

• Manage a portfolio of EMEA customers as their primary post-sales technical advisor, developing a deep understanding of the NodeZero platform to guide successful adoption.
• Cultivate champions with security leaders—from analysts to CISOs—and guide them through the lifecycle of adoption, expansion, and advocacy.
• Deliver technical onboarding and enablement to drive adoption of NodeZero, ensuring customers realize maximum value.
• Proactively identify customer needs and potential challenges, suggesting solutions that improve their experience and enhance their cybersecurity posture.
• Partner closely with IT and Security teams to help interpret pentest results, prioritize remediation, and guide long-term offensive security strategy.
• Collaborate closely with Sales and Renewals teams to drive retention and growth by identifying expansion opportunities.
• Act as a customer advocate, relaying customer feedback and technical issues to our internal teams.
• Conduct regular check-ins and quarterly business reviews to align on strategy and showcase business outcomes.
• Contribute to documentation, training materials, and repeatable playbooks to scale technical success across the region.
• Maintain detailed records of customer health and touchpoints using internal CS platforms.

What We’re Looking For

• 5+ years in Customer Success, Technical Account Management, or Client Services within a SaaS cybersecurity environment.
• In-depth knowledge of cybersecurity practices and principles; relevant certifications (e.g., CompTIA Security+, CISSP) are highly preferred.
• Strong customer acumen—able to align solutions to business priorities and present clearly to both technical and executive stakeholders.
• Experience managing a book of business with revenue targets.
• Startup or high-growth company experience is preferred.
• Comfortable with tools like Salesforce, Gainsight, and JIRA; detail-oriented and organized.

Perks of Horizon3.ai

• Inclusive Team: We value diversity and promote an inclusive culture.
• 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.
• Remote Work: We are a 100% remote company.
• Competitive Compensation: We offer competitive salary, equity, and benefits.

You Belong Here

Horizon3 is not just an equal opportunity employer - we are a community that values diversity, equity, and inclusion as fundamental principles of our culture and success. We welcome candidates from all backgrounds and experiences, and we encourage all qualified individuals to apply.

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee.