Senior Customer Success Manager – Enterprise SaaS Portfolio (£1.5‑2M) – Driving Net Revenue Retention, Upsell & Expansion at arenaflex

Why arenaflex?

At arenaflex we are on a mission to transform the way in‑house recruitment teams attract, hire, and onboard top talent. As a high‑growth HR‑tech startup, we have built a mature, market‑validated product that is already delivering measurable value to some of the world’s most demanding enterprises. Our customers love us because we combine cutting‑edge technology with a human‑first approach to success. If you thrive in fast‑moving SaaS environments, love turning data into action, and want to be part of a company that is reshaping the future of work, this is the role for you.

About the Role

This is a high‑impact, hands‑on position where you will own a strategic book of business valued at approximately £1.5‑2 million. You will be the trusted advisor for a portfolio of 40+ enterprise customers, balancing proactive, tech‑driven engagement with in‑person relationship building when it matters most. Your North Star will be Net Revenue Retention (NRR) – ensuring customers stay, adopt the platform fully, and uncover new opportunities for upsell and expansion.

Key Responsibilities

• Drive Commercial Outcomes: Own NRR for your portfolio by retaining customers, mitigating churn risk, and proactively identifying upsell and expansion opportunities.
• Strategic Relationship Management: Build and nurture senior stakeholder relationships across accounts, fostering advocacy and ensuring high sentiment that fuels renewals and growth.
• Success Planning: Partner with clients to define success metrics, develop tailored success plans, and align them with their business objectives.
• Upsell & Expansion Leadership: Lead conversations around additional value, craft compelling business cases, and close incremental revenue.
• Customer Voice Champion: Serve as the internal advocate for the customer, delivering actionable insights to Sales, Product, Engineering, and Support teams.
• Health Monitoring & Analytics: Track, analyze, and act on customer health metrics, turning data into strategic initiatives that reduce risk and maximize growth.
• Cross‑Functional Collaboration: Work closely with the Support team to ensure seamless issue resolution and with the Product team to influence roadmap priorities.
• Continuous Learning: Stay abreast of product releases (monthly) and industry trends to provide expert guidance to clients.

Tech Stack You’ll Leverage

Google Workspace, Notion, Slack, Zoom, HubSpot, Intercom, Linear, Guru – all the tools you need to stay organized, communicate effectively, and deliver world‑class service.

Who We’re Looking For

Essential Qualifications

• 3+ years of proven experience in Customer Success within B2B SaaS, with a track record of driving renewals, upsell, and expansion (ideally managing a portfolio >£1 M).
• Demonstrated ability to meet or exceed NRR targets and to develop strategic account plans.
• Strong commercial acumen – comfortable building business cases, negotiating, and influencing senior stakeholders.
• Entrepreneurial mindset – proactive, creative, and comfortable thriving in a fast‑changing startup environment.
• High ownership mentality – you treat your portfolio as your own business, taking initiative and delivering results without constant supervision.
• Data‑driven approach – adept at analyzing health metrics, spotting trends, and translating insights into actionable strategies.
• Excellent communication and presentation skills, both written and verbal, with the ability to convey complex ideas simply.
• Based in the UK, authorized to work, and willing to travel up to 20 % of the time for on‑site client visits.

Preferred Experience

• Background in HR‑tech or recruiting technology, or direct recruiting experience (agency or in‑house).
• Experience in an early‑stage startup or high‑growth SaaS environment, where you have worn multiple hats and contributed to rapid scaling.
• Familiarity with G2, Capterra, or similar review platforms and a track record of contributing to positive customer sentiment.
• Previous exposure to product development cycles and the ability to provide constructive feedback that shapes product direction.

Core Skills & Competencies

• Relationship Building: Ability to develop trust‑based relationships with C‑level executives and operational leaders.
• Strategic Thinking: Capacity to see the big picture, align customer goals with arenaflex’s value proposition, and drive long‑term success.
• Problem Solving: Calm under pressure, capable of juggling multiple accounts at different lifecycle stages while delivering solutions quickly.
• Communication: Clear, concise, and persuasive storytelling that influences decision‑makers.
• Adaptability: Comfortable with rapid product releases and evolving customer needs.
• Collaboration: Works seamlessly with Sales, Product, Engineering, and Support to create a unified customer experience.

Career Growth & Learning Opportunities

At arenaflex, your career trajectory is limited only by your ambition. As you master your portfolio and consistently exceed NRR targets, you will have clear pathways to senior leadership roles such as Senior Customer Success Manager, Customer Success Lead, or even Head of Customer Success. We invest heavily in continuous learning – you will receive an annual learning budget, access to industry conferences, and mentorship from senior executives who have built successful SaaS businesses from the ground up.

Compensation, Perks & Benefits

While exact figures will be discussed during the interview process, we offer a competitive base salary, performance‑based bonuses tied to NRR, and meaningful equity participation. Our benefits package is designed to support your health, wellbeing, and work‑life balance:

• Gold‑Plated Healthcare: Comprehensive medical, dental, and optical coverage for you and your family.
• Unlimited Holidays: Take the time you need to recharge – we trust you to manage your workload responsibly.
• Mental Health Support: Unlimited, immediate access to professional counseling through Spill.
• Retirement Matching: Competitive 401(k)/pension matching to help you achieve long‑term financial goals.
• Remote‑First Culture: Work from anywhere in the UK (or wherever you are most productive) with a flexible schedule.
• Equity Ownership: Share in the success you help create – meaningful stock options are part of the package.
• Generous Parental Leave: Up to 16 weeks of fully paid leave for new parents.
• Learning Budget: Annual funds for courses, books, certifications, or any development you choose.
• Top‑of‑the‑Line Equipment: MacBook Pro, 4K monitors, and all the tools you need to excel.
• Supportive Team Culture: Smart, driven, and kind colleagues who celebrate each other’s wins and help each other grow.

Our Culture & Values

arenaflex’s culture is built on a set of core values that guide everything we do – from product development to customer interactions. We believe in:

• Customer Obsession: Our customers are at the heart of every decision.
• Ownership: We act like owners, taking responsibility for outcomes and continuously improving.
• Transparency: Open communication, honest feedback, and clear expectations.
• Innovation: We experiment, iterate, and embrace change to stay ahead of the market.
• Collaboration: Success is a team sport – we win together.

When you join arenaflex, you become part of a community that values growth, celebrates diversity, and encourages you to bring your authentic self to work every day.

How to Apply

If you are ready to make a tangible impact on a fast‑growing HR‑tech leader, we want to hear from you. Click the link below to submit your application, and let’s start a conversation about how you can help shape the future of recruitment success at arenaflex.

Apply Now – Customer Success Manager at arenaflex