Customer Success & Engagement Lead - UK

About Mimo

Mimo is an AI-native workflow automation platform built for accounting firms. We help accountants eliminate the manual, repetitive work that dominates month-end close - giving them back time to do the work that actually matters. We're a 35-person team, backed by leading VC investors (Northzone and Project A), and growing fast with a focused accounting firm ICP. We have a rapidly growing base of accounting firm customers across the UK's top 10-250 practices - and we need the right person to make sure every single one of them succeeds.

The Role

Mimo is at an inflection point - pipeline and onboarding volumes are growing fast, and our customer base is genuinely excited about the product. We're looking for the person who will own the post-sale motion and define what exceptional usage looks like for our customers. This is a revenue & engagement role. You'll own onboarding, retention, and expansion - and you'll be held to the same commercial rigour as our sales team. The right person won't just keep customers happy - they'll turn them into Mimo's most powerful growth engine. The AI opportunity is real and it's yours to take. At Mimo, you won't be managing relationships the old way - you'll be building a CS motion that leverages AI to deliver faster onboarding, smarter health monitoring, and proactive expansion at a scale most CS teams can't match. If you're already using AI to do more with less, you'll feel at home here. For the right candidate - someone who combines genuine warmth with commercial sharpness, and who can both run accounts themselves and lead others doing the same - the path to CS & Commercial leadership is real. You'll report directly to the CEO, with full visibility into company strategy and growth trajectory from day one.

What You'll Do

• Own onboarding, activation and engagement end-to-end for new UK accounting firm customers - getting them live fast and driving early adoption.
• Manage a portfolio of active mid-market & enterprise accounts, maintaining deep relationships with both senior stakeholders and users.
• Lead the motion for our Engagement programme - managing a complex, hybrid sales and delivery process where Mimo Accountants work on-site at customer firms to customise workflows and automate their tech stack.
• Identify and close expansion opportunities within existing accounts, owning retention and expansion with the same rigour a sales team brings to pipeline.
• Coach and manage a growing team of CSMs and Engagement Associates - running account reviews, supporting implementation and driving user love.
• Build and iterate on the CS playbook: onboarding frameworks, health scoring, QBR templates, escalation processes.
• Feed customer insight back to product, sales, and marketing to sharpen Mimo's roadmap and positioning.
• Work closely with the CEO and exec team on retention strategy and CS infrastructure.

What We're Looking For

Must Haves

• Commercial ownership of retention and expansion: you have personally owned NRR targets - not just relationship health scores. You know what it means to be accountable for churn and expansion as revenue outcomes.
• High-touch account management at strategic level: you've managed complex, senior relationships. You're trusted by partners and decision-makers, as well as day-to-day users.
• Natural leader: you coach and level-up people around you - account reviews, call debriefs, process walk-through are not tick-box exercises, but development forums.
• Process builder: you've built or significantly improved an operating model from scratch - onboarding playbooks, health frameworks, QBR cadences. You don't wait to be handed a system; you build one.
• Startup DNA: you've worked in an environment where the playbook was being written, not handed to you. You're comfortable with ambiguity and energised by building from scratch.
• AI fluency: you actively use AI tools to scale your own output and have a clear point of view on how AI is changing your profession.

Strong Signals

• Accounting and/or professional services experience - have studied or worked in accounting, understands how firms are structured, how financial close processes run, and what makes an accountant's day painful. You don't need to be a qualified accountant, but you speak the language.
• Experience in CS at a SaaS company selling into UK accounting firms, professional services, or adjacent workflow or practice management tools - you understand how these firms operate and what makes them stay.
• Currently a CS Lead or Manager at a fast growing company, managing a book of business in the top tier of your team.
• Have managed at least two CSMs or CS Associates.
• Comfortable owning expansion & strategic conversations - has sourced or closed upsells directly, not just passed them to sales.

Not a Fit If

• You see CS as a support function rather than a revenue function.
• You expect to delegate relationship management to junior team members once you're in the door.
• You need a fully built playbook and infrastructure to operate effectively.

How to Apply

Apply here, and add a note on:

• What SaaS product you have managed CS for, and what types of customers.
• One commercial result that you're proud of and why.
• How you use AI in your current CS workflow.