Machine Learning Engineering Manager - Growth
About The Company
About Cleo
At Cleo, we're not just building another fintech app. We're embarking on a mission to fundamentally change humanity's relationship with money. Imagine a world where everyone, regardless of background or income, has access to a hyper-intelligent financial advisor in their pocket. That's the future we're creating.
Cleo is a rare success story: a profitable, fast-growing unicorn with over $300 million in ARR and growing over 2x year-over-year. This isn't just a job; it's a chance to join a team of brilliant, driven individuals who are passionate about making a real difference. We have an exceptionally high bar for talent, seeking individuals who are not only at the top of their field but also embody our culture of collaboration and positive impact.
If you’re driven by complex challenges that push your expertise, the chance to shape something truly transformative, and the potential to share in Cleo’s success as we scale, while growing alongside a company that’s scaling fast, this might be your perfect fit.
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About The Role
We're looking for an exceptional ML Engineering Manager to lead the Machine Learning efforts across our Growth team - the squad responsible for making smart, personalised decisions about what each of our 4M+ users sees, when they see it, and how we optimise for long-term value.
You'll manage a team of talented ML Engineers and collaborate with Marketing Engineers, Product Designers, PMs, and Data Scientists to build the systems that drive revenue growth while maximising lifetime value (LTV) for every single user. This is a high-impact role where you'll directly influence how we grow, retain, and monetise our user base.
The Growth team spans two squads: Growth Marketing (handling acquisition, channels, campaigns) and Growth Personalisation (handling on-app prompts, offers, and recommendations). Together, we maximise revenue while protecting long-term health.
What We're Building
ML-powered prompt recommender systems that decide which offer or action to show each user
Personalised messaging and incentive systems based on user context and history
Incrementality testing to measure true causal lift from our interventions
Multi-armed bandits and online learning to optimise in near real-time
Scoring and ranking systems that balance short-term revenue with long-term retention
What You’ll Be Doing
Lead ML Strategy & Delivery
Own the ML roadmap for Growth, working with the PM and leadership to prioritise high-impact projects
Lead the design and delivery of systems that personalise prompts, offers, and messaging to individual users
Drive continuous improvement across ML models, from concept to experiment to production
Build & Mentor Your Team
Recruit, onboard, and develop 3-5 ML Engineers (mix of IC and growing managers)
Create a high-performing culture where people want to do their best work
Balance mentorship with accountability - push the team to ship quality work quickly
Support career growth and technical development; create clear pathways for levelling up
Collaborate at Scale
Work closely with Growth Marketing Engineering on infrastructure, experimentation, and deployment
Partner with Product on feature prioritisation and user experience design
Engage Analytics on metrics, instrumentation, and incrementality testing
Communicate ML impact clearly to leadership and across the business
Own Technical Excellence
Review ML designs and code; ensure quality without becoming a bottleneck
Guide architectural decisions on model serving, latency, scalability
Maintain (and improve) the team's ML infrastructure and tooling
Lead incident response when models or systems degrade in production
Drive Experimentation & Learning
Champion a test-driven approach to ML - we measure impact, not just accuracy
Ensure robust experiment design, holdout groups, and statistical rigor
Build a learning culture where failures are dissected and shared
Publish learnings - both internally (to other teams) and externally
About You
You're a strong technical leader with hands-on ML experience, particularly in areas like:
Recommender systems & personalization - ranking models, candidate generation, multi-armed bandits, contextual decision-making
Uplift modelling & incrementality testing - understanding causal impact and incremental lift
Ad targeting & auction systems - optimising bidding, audience selection, and campaign performance
Marketing mix modelling (MMM) - attribution, channel contribution, budget allocation
You've shipped ML products at scale, managed teams (ideally 3-5 engineers), and you understand the balance between rigorous experimentation and speed to market. You care deeply about bringing good vibes while pushing the team to make it happen, and you're genuinely excited by the technical challenges in personalisation and growth.
What Makes You a Good Fit
Technical depth: You can code, debug, and review ML systems. You're not a pure manager, you're in the trenches with your team on high-impact projects.
Growth mindset: You learn at speed, adapt quickly, and aren't afraid to challenge assumptions with data. You see every project as a chance to level up the team's capabilities.
No bullshit: You're direct, honest, and pragmatic. You say what you mean and you mean what you say.
Cross-functional leadership: You can translate between ML complexity and business impact. You collaborate naturally with PMs, Data Engineers, and Analytics - no silos.
User-centric: You obsess over impact - not just model accuracy, but real-world outcomes like retention, revenue, and lifetime value.
What We're Genuinely Excited About
You've built recommender or ranking systems at scale - Spotify playlists, Netflix recommendations, Amazon product ranking, Pinterest pins, social media feeds, ad targeting. That context is gold.
You've done causal inference work - incrementality testing, uplift modelling, experimentation design. You understand the difference between correlation and causation.
You've managed through hypergrowth - you've scaled a team, navigated process changes, and kept quality high while shipping at velocity.
You have growth or marketing domain experience - you understand LTV, CAC, channel economics, attribution, and retention. You speak fluent "growth."
You've open-sourced or published ML work - papers, blog posts, talks. You like to share knowledge.
Technical Experience
What we're looking for
5+ years in ML/Data Science roles, with at least 2+ years in a leadership or senior technical IC capacity
Hands-on experience shipping ML products end-to-end (not just notebooks) - ideally in personalisation, recommender systems, or growth
Strong fundamentals in statistical inference, experimental design, and causal reasoning
Production ML experience: model serving, latency optimisation, A/B testing, monitoring
Comfortable with Python, SQL, and cloud platforms (GCP, AWS, etc.)
Experience with typical ML stacks (scikit-learn, XGBoost, TensorFlow/PyTorch, or similar)
Leadership Experience
Track record of building and scaling high-performing teams
Comfortable hiring, onboarding, and developing engineers from L2 to L4+
Experience giving technical feedback, code reviews, and architectural guidance
Ability to balance autonomy with accountability - you know when to step in and when to empower
Comfort navigating ambiguity and making decisions with incomplete information
Mindset & Values
You genuinely care about impact - shipping models that drive real business outcomes, not just optimising metrics in isolation
You're intellectually curious and humble - you don't have all the answers and you're excited to learn from your team
You're a teacher and a learner - you enjoy helping others grow while continuing to develop your own skills
You can operate effectively across technical and non-technical contexts - you translate for stakeholders without over-simplifying
You have strong communication skills - you can explain complex ML concepts clearly, both to engineers and to non-technical partners
The recruitment process
Interview with a Recruiter (30 mins)
Interview with the Hiring Manager (30 mins)
Python Programming Interview (45 mins)
Whiteboard Interview (60 mins)
Management Skills Interview (60 mins)
What do you get for all your hard work?
A competitive compensation package (base + equity) with 3-yearly reviews, aligned to our termly OKR planning cycles.
The salary bandings for this position are: £150,000 - 170,000 London, Hybrid / £140,000 - 160,000 UK, Remote
Work at one of the fastest-growing tech startups, backed by top VC firms, Balderton & EQT Ventures
A clear progression plan. We want you to keep growing. That means trying new things, leading others, challenging the status quo and owning your impact. Always with our complete support.
Flexibility. We can’t fight for the world’s financial health if we’re not healthy ourselves. We work with everyone to make sure they have the balance they need to do their best work
Work where you work best. We’re a globally distributed team. If you live in London we have a hybrid approach, we’d love you to spend one day a week or more in our beautiful office. If you’re outside of London, we’ll encourage you to spend a couple of days with us a few times per year. And we’ll cover your travel costs, naturally.
Company-wide performance reviews every 4 months
Generous pay increases for high-performing team members
Equity top-ups awarded across all levels in performance reviews
25 days annual leave a year + public holidays (+ an additional day for every year you spend at Cleo, up to 30 days)
1 month paid sabbatical after 4 years at Cleo
6% employer-matched pension in the UK
Private Medical Insurance via Vitality, dental cover, and life assurance
Online mental health support via Spill
Enhanced parental leave
Workplace Nursery Scheme
Paid for access to multiple AI platforms (ChatGPT, Codex, Claude)
Access to the latest AI coding models
Pick your kit - choose between a Windows or an Apple computer
Regular socials and activities, online and in-person
And many more!
We strongly encourage applications from people of colour, the LGBTQ+ community, people with disabilities, neurodivergent people, parents, carers, and people from lower socio-economic backgrounds.
App access for people in the UK & Europe: If you are an iOS user, please use this link to sign up to our TestFlight version of the app, so you can have a play around with the functionality and features:
https://testflight.apple.com/join/fDG9hWng
By submitting this application, I confirm that all the information given by me in this application for employment and any additional documents attached hereto are true to the best of my knowledge and that I have not wilfully suppressed any material fact. I confirm I have disclosed if applicable any previous employment with Cleo AI. I accept that if any of the information given by me in this application is in any way false or incorrect, my application may be rejected, any offer of employment may be withdrawn or my employment with Cleo AI may be terminated summarily or I may be dismissed. By submitting this application, I agree that my personal data will be processed in accordance with Cleo AI's
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