Senior Data Scientist - Network Simulation

Relay's network is scaling fast. The decisions that shape that growth - where to expand, how to price, where to invest - rest on models that simulate how the network behaves and how it evolves as density, geography, and operating models change. We have an MVP tool for this today; we need someone to help productionise it and build the next generation of strategic models on top of it. You'll be a core contributor to Relay's digital twin - a network simulator that captures our unit economics end-to-end, from first-mile collection through sortation, middle-mile and last-mile. It's already in use by finance, but it's a living system: every operating-model change, new service type, or commercial scenario means upgrading a component, adding a model, or building a new view. Your job is to help keep it accurate and to extend it where the business asks new questions.

Responsibilities

Productionise the MVP network simulation tool and build next generation strategic models; Evolve the digital twin by understanding cost components and upgrading models systematically; Build new strategic models and forecasts (volume forecasts, predictive models, scenario tooling); Partner with finance team to translate questions into modelling problems and provide dynamic tools; Contribute to the roadmap by prioritising and shipping model improvements; Work across production stack (Python, SQL, APIs, frontend) as needed

Requirements

Strong modeller who thinks in systems; Builder who understands problems and ships useful iterations; Fluent in Python and SQL; Comfortable doing own data engineering; Strong software engineering principles in modelling work; At ease in a production codebase (Python, SQL, APIs, frontend); Experience with financial modelling, forecasting, or simulation; Knows ML and uses it where it materially improves accuracy; Communicates clearly with non-technical partners; Cares about the problem more than the technique; Takes ownership of work; Ability to learn a complex operational domain quickly and model it well

Nice to have

Logistics or delivery network experience

Benefits

Generous equity with annual top-ups; Private health & dental coverage; 25 days of holidays; Enhanced parental leave; Hardware of your choice; Extensive perks including gym subsidies, cycle-to-work, Friday office lunch, covered Uber home and dinner for late nights