Machine Learning Performance Engineer

At Cleo, we're not just building another fintech app. Imagine a world where everyone, regardless of background or income, has access to a hyper-intelligent financial advisor in their pocket. 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. 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 Machine Learning Engineer specialising in Marketing Science to become a cornerstone of our high-performing team. As the first Machine Learning Engineer in this squad, you’ll harness data to unlock insights into channel performance, support to optimise marketing strategies, and drive our growth. Working closely with our Director of Performance Marketing, Marketing Analytics Manager, and cross-functional teams, your work will directly impact how we attract, engage, and retain Cleo’s users. Marketing Measurement: Building out some of and improving on Cleo’s marketing measurement toolkit, including Marketing Mix Models (MMM), attribution modelling, and incrementality testing to provide the team with clear insights into the drivers of overall and channel performance. Develop and optimise predictive models that forecast user lifetime value, ensuring data-driven channel optimisation and decisions that maximise Return On Ad Spend. Budget Allocation Tools: Create scalable, automated decision-support tooling that optimises the distribution of our marketing budget across channels. These tools will integrate data from multiple sources including MMM, incrementality tests, and our single source of truth (SSOT) data to maximise ROAS. Marketing Lift Tests: Work with our performance marketing team and marketing platforms (Meta, Tiktok, Apple etc) to design and implement lift studies that enhance our understanding of channel performance & incrementality. Brand Marketing Campaign Analysis: Develop causal inference models to provide deeper insights into the performance and uplift of our brand marketing campaigns on awareness and acquisition. Continuously review and refine data processes, collection and tooling, collaborating with engineering to maximise efficiency. 3+ years in Data Science, with a focus on Marketing Science or a related field. ~ Strong background in statistical analysis, including Marketing Mix Modelling and Predictive LTV modelling. ~ Excellent knowledge of both Data Science (Python, SQL) and production tools (Airflow). ~ Experience of shipping tested models which make predictions in batch or real time. ~ A proactive approach to learning new technologies and stepping outside your comfort zone, whether building data pipelines, or integrating data sources. A keen interest in leveraging advanced analytics to drive financial technology innovations. A competitive compensation package (base + equity) with bi-annual reviews, aligned to our quarterly OKR planning cycles. A clear progression plan. We can’t fight for the world’s financial health if we’re not healthy ourselves. 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. And we’ll cover your travel costs, naturally. ~ Company-wide performance reviews every 6 months. ~ Generous pay increases for high-performing team members. ~ 25 days annual leave a year + public holidays (+ an additional day for every year you spend at Cleo, up to 30 days). ~6% employer-matched pension in the UK. ~ Private Medical Insurance via Vitality, dental cover, and life assurance. ~ Enhanced parental leave. ~1 month paid sabbatical after 4 years at Cleo. ~ Regular socials and activities, online and in-person. ~ Online mental health support via Spill. ~ 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. indicates a required field Phone * Do you require visa sponsorship in order to work in the UK? * GDPR Point of Data Transfer * This email is to notify you that personal data about you has been collected by Cleo AI Ltd (hereafter Controller), which is located at Cleo AI Limited LTD Telephone House, 69 Paul St, London EC2A 4NG, UK and can be contacted by emailing personal data was either obtained from publicly available sources (e.G. 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Because the European Union Commission has determined that United States data privacy laws do not ensure an adequate level of protection for personal data collected from EU data subjects, the transfer was subject to appropriate additional safeguards under [either the standard contractual clauses or the Privacy Shield]. Your personal data will be retained by Cleo AI as long as Cleo AI determines it is necessary to evaluate your application for employment. Under the GDPR, you have the right to request access to your personal data, to request that your personal data be rectified or erased, and to request that processing of your personal data be restricted. You also have to right to data portability. In addition, you may lodge a complaint with an EU supervisory authority. Data is shared with employees at Cleo AI who are involved in the hiring process or decision. Your data will be retained in our Applicant Tracking System as long as a candidate is interested in positions within the organisation, but not longer than one year. Data will be used for recruitment purposes only. Contact to complain, request copy or deletion of data you have commercial experience with Natural Language Processing? *