(Senior) Machine Learning Engineer

Cleo; España; Híbrido; EUR 88.028 - 140.845; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Base salary + equity

25 days annual leave

Private medical insurance

Employer pension (6% match)

Sabbatical after 4 years

Descripción de la vacante

Cleo is hiring (Senior) Machine Learning Engineers to build novel ML solutions aimed at improving users’ financial health. You’ll lead technical work with engineers, data analysts, and product teams, deploying models to production at scale for millions of users.

You’ll work across chatbots, classifiers, and ML systems that power Cleo’s payments platform, collaborating with external LLM providers and internal platforms, while mentoring peers and defining best practices.

Formación

• Proficiency in Python and SQL for data science and production tooling.
• Strong fundamentals in probability and statistics.
• Ability to diagnose problems and productionise research.
• Excellent communication to partner with product and commercial leaders.
• Contributions to the field through talks, blogs or open‑source projects.
• Advanced degree in a quantitative discipline or equivalent experience.

Responsabilidades

• Train and fine‑tune models to solve customer problems.
• Deploy models in production using the in‑house platform or external LLMs (OpenAI, Anthropic, GCP, AWS).
• Collaborate cross‑functionally with backend engineers, data analysts, and product teams.
• Lead technical work and drive change at the chapter level across squads.
• Mentor colleagues on model choices, architecture and evaluation.

Conocimientos

Python

SQL

Statistics

Probability

Communication

Cross‑functional

Educación

Advanced degree (quantitative)

Herramientas

In‑house ML platform

OpenAI

Anthropic

GCP

AWS

Descripción del empleo

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.

Follow us on LinkedIn to keep up to date with new product features and insights from the team.

About The Role

(Senior) Machine Learning Engineers at Cleo work on building novel solutions to real‑world problems. This really does vary but could be: creating chatbots to coach our users around their financial health, creating classifiers to better understand transaction data or even optimising transactions within our payments platform.

Ultimately, we’re looking for a brilliant (Senior) Machine Learning Engineer to join us on our mission to fight for the world’s financial health. You’ll be leading technical work within a team of adaptable, creative and product‑focused engineers, who train & integrate cutting‑edge machine learning across a variety of products and deploy them into production for millions of users. We understand our customers, we understand their pain, and we are passionate about helping them.

Check out this blog on Isabelle’s journey in ML at Cleo.

What You’ll Be Doing

• Training and fine‑tuning models to solve customer problems.
• Deploying these models into our production environments using our in‑house ML platform, or integrating with LLMs hosted by OpenAI, Anthropic, GCP, AWS and others.
• Working cross‑functionally with backend engineers, data analysts, UX writers, product managers, annotation teams, and others to ship features that improve our users’ financial health.
• Taking the initiative to propose & lead technical work towards problems that were previously unknown or poorly understood. Driving change at the chapter level that affects multiple squads.
• Mentoring & advising colleagues on their choices of models, architecture, and evaluation, promoting best practices for how we use LLMs.

Here are some examples, big and small, of the kinds of product feature work our ML Engineers have taken part in over the last year.

• Developed deeper understanding of users’ finances through models extracting meaning from transactional data. Think about your bank statement – how often do you not know what a transaction is?
• Developed contextual intent classifiers to understand what conversations users are having with Cleo, enabling control of how Cleo should respond.
• Building ML models to understand the actions that users have available to them in Cleo and provide those contextually in conversations.
• Built ML models to understand the risk of customers using bank transaction features and user activity.
• Built models to optimise the payment success for our customers and optimise the costs for the business. Think of this as a two‑sided optimisation problem.

What You’ll Need

• Excellent knowledge of both Data Science (Python, SQL) and production tools.
• A deep understanding of probability and statistics fundamentals.
• Big picture thinking to correctly diagnose problems and productionise research.
• Top tier communication skills, to be able to partner with Product and Commercial Leaders.
• Industry‑leading contributions to your field, communicated through conferences, blogs, talks or open‑source projects.
• Advanced Degree in a quantitative discipline or equivalent commercial experience.

Nice to have

• Strong experience with additional programming languages, such as Java, Scala, C++.
• Industry‑leading contributions to your field, communicated through conferences, blogs, talks or open‑source projects.

The recruitment process

• Interview with a Recruiter (30 mins)
• Interview with the Hiring Manager (30 mins)
• Python Coding Interview (45 mins)
• White‑boarding session (60 mins)
• Technical Discussion (45 mins)

What do you get for all your hard work?

• A competitive compensation package (base + equity).
• Mid‑level (L2)
  • London, UK Hybrid: £75,000 – £95,000 gross annually
  • UK Remote: £69,000 – £87,000 gross annually
  • Europe Remote: €78,750 – €99,750 gross annually
• Senior‑level (L3)
  • London, UK Hybrid: £95,000 – £120,000 gross annually
  • UK Remote: £87,000 – £110,000 gross annually
  • Europe Remote: €99,750 – €126,000 gross annually
• Work at one of the fastest‑growing tech startups, backed by top VC firms, Balderton & EQT Ventures.
• A clear progression plan.
• Flexibility.
• Work where you work best.
• 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!
• Final compensation will be determined based on the candidate’s seniority, qualifications, skills and previous experience.

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 Candidate Privacy Notice.