Why Rein?

Rein was founded to solve one of cybersecurity's toughest challenges: understanding how AI agents and applications behave in real time.

Our technology helps AI and Application security teams see risk as it really is. The result: faster, smarter security decisions based on what's actually happening inside your apps.

Backed by leading VCs, Rein is already trusted by companies across banking, energy, and SaaS.

We're looking for driven, ambitious people who know how to win. As our first Customer Success Manager, you'll build the CS function from the ground up — becoming a trusted advisor to our customers and a key partner to our go-to-market team.

Learn more about us here: https://reinsec.io/

As our Customer Success Manager, you'll build and maintain end-to-end relationships with our customers, helping them realize value from Rein's platform. As a trusted advisor, you'll leverage your domain expertise and problem-solving skills to help customers drive adoption and achieve business outcomes — working closely with Sales, Sales Engineering and Product Management to ensure our customers' success, drive growth, and secure renewals.

What You'll Do

• Own onboarding for new customers, ensuring a smooth handoff from Sales and a fast path to value
• Provide tier-one support, collaborating with Product and R&D to resolve more complex issues
• Build Customer Success Plans with assigned customers and Sales, establishing critical goals and KPIs, and track progress
• Establish regular touchpoints to review progress against technical and strategic objectives, including roadmap discussions
• Partner with Sales, R&D, and Product to solve complex customer scenarios and surface new use cases
• Develop trusted advisor relationships with stakeholders at every level, driving adoption and value
• Translate customer product usage data into actionable recommendations
• Identify and recommend upsell and expansion opportunities throughout the customer lifecycle
• Own customer health scoring and risk management, and program-manage escalations

What You Bring

• 5+ years of experience in an Account Management or Customer Success role at a SaaS vendor, systems integrator, or in-house practitioner
• Experience working with enterprise-level organizations and managing complex, multi-stakeholder relationships
• Track record managing an aggregate of $2M+ ARR, with upsell and expansion at 20%+ of total ARR
• Ability to translate business requirements into business value, partnering with Sales and Marketing on value-driven solutions
• Experience managing executive-level relationships and discussions
• Excellent moderation and communication skills

Who You Are

• A trusted advisor who builds credibility quickly with technical and executive stakeholders alike
• Self-sufficient and highly motivated, comfortable building a function from scratch in a fast-paced, early-stage environment
• Honest, direct, and solutions-oriented

Performance Indicators

• Gross renewal rate and net ARR growth (upsell & expansion opportunities with high win rate)
• Platform adoption and usage
• Churn and contraction rate
• Customer satisfaction



What We Offer

• Competitive compensation, equity, and benefits
• Flexible PTO and a remote-friendly work environment
• Work closely with the company's leadership team
• Real opportunity to build and shape the Customer Success function in a high-growth startup

If this sounds like a fit, we'd love to hear from you: careers@reinsec.io