Customer Success Manager

Harmonic Security lets teams adopt AI tools safely by protecting sensitive data in real time with minimal effort. It gives enterprises full control and stops leaks so that their teams can innovate confidently.

We are led by cybersecurity experts and backed by top investors including N47, Ten Eleven Ventures, and In-Q-Tel. We have achieved early traction and product-market fit with a world-class team, and we are now focused on building a category-defining company. This is your opportunity to join us early and shape not just a product, but a category.

**How We Work: AI-First by Design**

Harmonic exists to help enterprises adopt AI safely and at scale. We hold ourselves to the same standard. Everyone at Harmonic actively uses AI tools to do their best work, from research and writing to building processes and automating workflows. We expect every new hire to bring curiosity about AI and a willingness to use it to work smarter, faster, and more creatively. For some roles, that means tinkering and staying open to new tools. For others, it means building entirely new systems with AI at the core. We'll be clear about what we expect for each role, and we'll give you the tools and support to get there.

About The Team

You will report to the Director of Customer Success and work closely with Sales, Product, and Engineering team leaders. Our Customer Success team delivers a world-class experience for every customer. We don't believe in one-size-fits-all. Instead, we take a deep partnership approach to help customers realize their vision and achieve meaningful business outcomes through Harmonic.

About The Role

As a Customer Success Manager at Harmonic, you'll own the full customer lifecycle from onboarding through renewal for a portfolio of enterprise accounts. You'll be a trusted advisor to both executive and technical stakeholders, building the kind of deep partnerships that drive adoption, retention, and long-term value.

This role calls for someone who is genuinely comfortable operating across levels as confident as a security engineer through a deployment as presenting business outcomes to a CISO. You don't need to come from a purely technical background, but you'll need to earn the trust of technical buyers and speak their language. Whether your path here was through customer success, technical account management, or solutions engineering, what matters most is that you're energized by the customer relationship and committed to their success.

You'll also play a foundational role in helping Harmonic build the playbooks, processes, and metrics that will scale with us as we grow.

**What You Will Do**

• Serve as the primary point of contact for a portfolio of enterprise accounts, owning relationships at both the executive and technical level.
• Lead the full customer lifecycle from onboarding and deployment through adoption, renewal, and expansion.
• Run technical onboardings alongside customer security and IT teams - configuring integrations, walking through data flows, and ensuring Harmonic is embedded into the customer's environment correctly.
• Conduct Quarterly Business Reviews (QBRs) that connect product telemetry to measurable business outcomes and executive priorities.
• Proactively monitor customer health signals, identify risk early, and drive mitigation plans before issues escalate.
• Champion the voice of the customer internally - translating technical and strategic feedback into actionable input for Product and Engineering.
• Partner with Sales on expansion opportunities, building the case for upsell and identifying new stakeholders and use cases.
• Contribute to the CS playbook: help build the processes, tooling, and metrics that define how Harmonic delivers value at scale.

**What You Bring**

• 5–8\+ years in customer success, technical account management, or sales engineering - with a demonstrated preference and passion for the post-sale customer relationship.
• Experience leading complex enterprise onboardings and driving deep product adoption in technical environments.
• Strong analytical skills and fluency with CS metrics: NRR, GRR, CSAT, time-to-value, and product usage data.
• Exceptional communication skills - you can translate complex technical concepts for executive audiences and business value back into technical requirements.
• Highly organized, proactive, and adaptable - you raise your hand, take initiative, and go the extra mile for your customers.
• Familiarity with CRM and customer success tooling (e.g. HubSpot, Salesforce, Gainsight, or similar).
• Background in cybersecurity, data security, or AI governance.
• (Bonus): A technical foundation: you've worked alongside or directly with security, IT, or engineering teams and can hold your own in conversations about integrations, APIs, and enterprise security architecture.

**You Might Be a Fit If**

• You've come from a Sales Engineer or Technical Account Manager background and found that what energizes you most is the long-term customer partnership.
• You genuinely enjoy getting into the technical details of a deployment, not just coordinating them from a distance.
• You're excited about being an early-stage CS hire at a fast-growing startup and helping define what great looks like from the ground up.
• You're comfortable with ambiguity and thrive in environments where the playbook is still being written.
• You see AI as a tool to make your work sharper and faster - and you're already using it that way.

**Why Join Us**

This is not just a job. It is an opportunity to be part of a team that is redefining cybersecurity and AI safety. We believe today's talent is tomorrow's success, and we are committed to creating an environment where you can do the best work of your life.

• Competitive compensation and meaningful equity with a direct stake in Harmonic's success
• Comprehensive benefits including health, dental, vision, and 401k matching
• A small, passionate team that values transparency, creativity, and learning
• Thoughtful leadership that cares deeply about growth, impact, and people
• Annual global off-sites
• The chance to directly shape the revenue engine and culture of a category-defining company

**Harmonic's Core Values**

🌱 Flourish in the Unknown

We embrace new, unfamiliar situations that require initiative and rapid decision-making. We orient ourselves quickly and deliver results with minimal guidance.

🔥 Never Full

We raise our hands, take on challenges, and assist others whenever possible. We hunger for opportunities to learn and do more.

🤝 Perfect Harmony

We support one another to create cohesion and unity. We collaborate openly, share feedback honestly, and help everyone produce their best work