Junior Data Scientist – Marketing Analytics & Modeling

Fospha; Greater London; Hybrid; GBP 65,000 - 100,000; Full time

Job summary

Fospha, based in London, is seeking a Data Scientist to join its Data Science team, working within the Stream 3 workstream. The role involves attribution, marketing mix modelling, incrementality testing, and brand impact measurement.

You’ll contribute to models from methodology to production code and collaborate across the technical stack. This role suits someone with some commercial data science experience who wants to go deeper, taking on challenging work with a supportive team, ownership, and

Qualifications

• Some commercial data science experience — typically 1–2 years, or a strong placement/internship record alongside a quantitative degree.
• Strong Python and SQL, with the ability to collaborate on shared code and avoid technical debt.
• Deep knowledge of a handful of machine learning algorithms; not breadth for its own sake, but real understanding of a few methods and when they apply.
• Able to systematically debug unfamiliar code, using AI tooling to accelerate rather than guess.
• Strong AI fluency — you understand how to start a task with AI and QA outputs for accuracy and brevity.
• Confident completing work independently once scope is agreed; able to communicate with clients and colleagues with minimal assistance.
• Genuine attention to detail — noticing when numbers are wrong.

Responsibilities

• Own moderately difficult tickets end to end — investigations, model backtesting, production fixes, and pipeline work.
• Debug systematically across codebases, including unfamiliar repositories, using AI tooling to speed up onboarding.
• Write and review production code in Python and SQL to avoid technical debt and maintainability.
• Use QA automation and cloud tooling effectively — validate data science components of AWS pipelines.
• Communicate methodologies and findings to clients and colleagues with minimal senior support.
• Work with other teams to pin down acceptance criteria and requirements, avoiding blocks.

Skills

Python

SQL

Machine learning

Data visualization

Collaboration

Education

Quantitative degree (STEM)

Tools

AWS

AI tooling

Job description

Fospha, based in London, is seeking a Data Scientist to join its Data Science team, working within the Stream 3 workstream. The role involves attribution, marketing mix modelling, incrementality testing, and brand impact measurement.

You’ll contribute to models from methodology to production code and collaborate across the technical stack. This role suits someone with some commercial data science experience who wants to go deeper, taking on challenging work with a supportive team, ownership, and