Junior Data Scientist

Who you are

• Statistical foundations. You have a background in probability and statistics from a quantitative field – typically a degree (or recent/final-year Master's) in Statistics, Mathematics, Physics, or similar. You reason about uncertainty and calibration as first-order concerns
• Research mindset. You're curious about new methods and actively look for better ways to do things. You try them out, not just read about them
• Judgement. You critically evaluate model output – yours, a colleague's, or an LLM's – and can explain why a choice is right. You defend your reasoning under challenge, and challenge others' when the evidence points elsewhere
• Analytical ownership. You take workstreams from framing to a landed decision, with support on solution design where you need it. You like to move fast, iterate, and update on new evidence rather than chase perfection
• AI fluency. You use AI as a primary tool. You prototype with it, automate with it, and use judgement on where it helps and where it doesn't
• Communication. You write and speak clearly, directly, and concisely. You adapt technical detail for non-technical colleagues in sales and marketing
• Domain experience. You have worked on marketing, sales, or customer acquisition problems
• Causal inference and experimentation. You have designed or analysed experiments where distinguishing signal from noise mattered – A/B tests, quasi-experiments, or lift studies
• Marketing mix or attribution modelling. You have used or contributed to models that quantify channel impact or optimise spend
• Bayesian methods. You have used hierarchical models, MCMC, or Bayesian updating in real work
• Production ML. You have built and shipped supervised ML models end to end – exploration, training, deployment, monitoring
• Python. The stack the team uses

What the job involves

• You'll design experiments and build the statistical models that shape how iwoca reaches new customers. You'll practise mastery of your craft, mentored by the team's data scientist, with iwoca's wider data science community around you
• The Sales & Marketing team, also known as Direct Acquisition, owns how iwoca reaches UK small businesses – across paid and organic marketing channels and direct sales
• The team is autonomous and cross-functional, bringing together Marketing, Sales, Brand, and AcquiTech – iwoca's acquisition technology team, which includes software engineering, product, design, and data science. As a Data Scientist, you'll work with people across each function
• As a Data Scientist in the Direct Acquisition team, you'll design experiments and build the statistical models that shape how iwoca reaches its next customers. Your findings feed directly into how we invest in sales and marketing
• You'll work alongside the team's data scientist, who mentors you closely as you take on more ownership
• Experimentation. You'll design and evaluate experiments so decisions on sales and marketing rest on evidence
• Modelling. You'll build models that solve the team's business problems, with input on approach and solution design
• Community and mastery. You'll join iwoca's wider data science community – analysts, data scientists, and statisticians – to align on methodology and develop your expertise across acquisition

Benefits

• Work where you work best: Twice a year we rent houses in places like Sicily and the French Alps where each team can work together for a week poolside. We champion flexible working in all our teams
• Invest in iwoca: We want people to be invested in iwoca's success so after six months you'll be awarded share options
• Keep yourself healthy: We offer comprehensive health insurance and cash plans. You'll also get gym discounts and we host yoga classes in the office every week
• Start (and end) your day right: Each floor of iwoca HQ has a fully stocked fridge for breakfast and every Friday we unwind with beers and wine
• Life-work balance: We know your life outside of work comes first. We offer enhanced maternity and paternity leave for new parents plus a nursery benefit. We also have unlimited unpaid leave
• Learning and development: Whether you want to learn to code, experiment with motion design, or beat cognitive biases, you'll have time and budget to invest in your professional development