Location: London, 4 days in office (Shoreditch)
Salary: Up to £240,000 + Bonus + Compelling Equity
We’re working with a high-growth, profitable technology company building a new category in performance marketing.
Their platform rewards a global user base of tens of millions for engaging with digital products, creating a powerful acquisition channel for some of the world’s largest brands.
The business has achieved significant scale and revenue without external funding and continues to grow rapidly across international markets.
The opportunity
This is an early hire into a newly forming London engineering team.
You’ll work on a core problem at the heart of the business: predicting user value in real time and optimising personalised reward systems at scale.
The role is hands‑on, with ownership across the full lifecycle, from modelling to production deployment and iteration.
What you’ll do
Design, build, and scale production-grade ML systems
Develop real‑time models to predict individual user value (pLTV)
Optimise personalised reward systems based on behaviour and market dynamics
Identify and diagnose underperforming campaigns using causal inference
Own end‑to‑end delivery: modelling, deployment, monitoring, and optimisation
Apply statistical methods (A/B testing, regression, probability) to ensure robustness
Align ML solutions with business priorities and commercial impact
Partner with product and engineering to translate problems into data‑driven systems
Contribute to technical direction and raise engineering standards
Types of problems you’ll be solving
Real‑time valuation of users across tens of millions of data points
Designing adaptive reward systems under behavioural drift and market shifts
Understanding not just what is happening in campaigns, but why
Balancing model accuracy, latency, and commercial outcomes at scale
You should have
Strong experience building and deploying ML systems in production
Deep understanding of statistics (A/B testing, regression, probability)
Strong programming skills in Python and SQL
Experience working with cloud‑based infrastructureAbility to operate in high‑scale, data‑intensive environments
A product‑oriented mindset with focus on impact
Strong communication skills across technical and non‑technical stakeholders
Experience in adtech, monetisation, or gaming
Familiarity with metrics such as pLTV, retention, or ROAS
Understanding of incentive systems or user behaviour modelling
Tech environment
Production ML systems operating at large scale
Real‑time data pipelines and decision systems
Cloud‑native infrastructureStrong emphasis on statistical rigour and causal inference
Tight feedback loops between models and real‑world outcomes
Why it’s compelling
Work on a genuinely difficult ML problem with immediate feedback loops
Direct impact on a product used by tens of millions of users
Profitable, high‑growth business with strong fundamentals
Early‑stage London team with influence over technical direction
High ownership and exposure to core business systems
Competitive compensation with performance upside
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Site Lead, Data & ML (240,000 | RecSys | Python) in London employer: Dex
At Dex, we pride ourselves on being an exceptional employer, offering a dynamic work culture that fosters innovation and collaboration. Our London-based team enjoys a hybrid working model, competitive benefits, and ample opportunities for professional growth, all while contributing to cutting-edge technology in the healthcare sector. Join us to make a meaningful impact in real-time systems and edge deployment, surrounded by a supportive team dedicated to excellence.
