Junior Data Scientist I

JobsCloseBy Editorial Insights

MarketCast seeks a Junior Data Scientist - Product to join its London or Reading team, full time onsite with hybrid options. You will design, engineer, and maintain data pipelines and backend services, write production-grade Python and SQL, assist with analyses and audience segmentation, and help deploy AI and NLP features under senior guidance. The role emphasizes clean data, engineering discipline, and durable product features, with collaboration across product managers, engineers, and clients. They value practical experience over formal degrees and seek curiosity, solid coding, and a love of technical depth. To apply, showcase end-to-end projects, pipelines, MLOps, testing, and measurable outcomes; share a portfolio or GitHub and demonstrate teamwork and a growth mindset aligned with MarketCast values.

Junior Data Scientist - Product

London, UK, Reading, UK

Role Impact:
As our Junior Data Scientist - Product, you'll be a pivotal player on our Data Science Product Team, which currently comprises about 15 data scientists with varying levels of seniority.

The Junior Data Scientist - Product plays a foundational role in supporting the design, engineering, execution, and delivery of advanced data science projects and market research products at Marketcast. Operating at the intersection of quantitative market research, software engineering, and artificial intelligence, this position focuses on building the backend systems and data pipelines that clean, process, and analyse complex datasets to extract actionable consumer insights. On a daily basis, the Junior Data
Scientist assists in writing production-quality code, developing and maintaining data pipelines, implementing machine learning models, and translating analytics into robust, reusable product features under senior guidance. By ensuring high data quality, engineering rigour, and contributing to innovative product features, this individual directly enhances the reliability and scalability of the organisation's media and entertainment analytics.

We're Looking For:

• Data Engineering and Pipeline Development – Design, build, and maintain reliable data pipelines that clean, preprocess, and structure complex quantitative datasets using Python, SQL, pandas, and modern data tooling. This technical processing is performed systematically and reproducibly, with an emphasis on well- structured, version-controlled, and testable code to prepare raw survey and consumer data for downstream statistical models. Ensuring clean inputs and resilient
  pipelines directly prevents model drift and maintains the reliability of product outputs. Success in this responsibility is defined by the timely delivery of error-free, analytical-ready, and maintainable data pipelines to senior data scientists.
• Quantitative Analysis & Modelling - Assist in executing statistical analyses, regression modelling, and audience segmentation under the guidance of senior team members, with a strong emphasis on mathematical rigour and a sound understanding of the methods being applied rather than their black-box use.
• Backend & Software Development - Contribute to the backend services, APIs, and codebases that power our data products, writing clean, tested, and well-documented code under senior guidance. The analyst works within standard software engineering practices - version control, code review, automated testing, and CI/CD - to ship features that are reliable and maintainable rather than one-off scripts. This software-first approach ensures our analytical work translates into durable product infrastructure. Success is measured by code quality, adherence to engineering standards, and the stability of contributions in production.
• Infrastructure & Deployment - Support the deployment, monitoring, and scaling of data science workloads across our cloud and infrastructure stack (e.g. containers, orchestration, and managed cloud services) under supervision. The analyst helps operationalise models and pipelines so they run reliably and cost-effectively at scale,
  contributing to the team's MLOps and engineering practices. This focus on robust infrastructure reduces manual intervention and improves the reliability of our products. Performance is evaluated on the stability, reproducibility, and efficiency of deployed workloads.
• AI & LLM Integration - Support the integration of artificial intelligence APIs, large language models (LLMs), and natural language processing pipelines into existing data products. Under supervision, the analyst helps configure frameworks to streamline analytical workflows, saving dozens of hours of manual coding on client projects. Performance is evaluated on the efficiency, robustness, and classification accuracy of the automated NLP routines.
• Data Quality & Validation - Execute rigorous quality control protocols across all assigned data products and research databases, including automated tests and validation checks wherever possible. The Junior Data Scientists systematically validate schemas, sample distributions, and statistical weights to verify data integrity, treating data validation as an engineering discipline. This preventative auditing mitigates the risk of reporting flawed conclusions to high-profile entertainment clients.
  Successful execution is measured by the complete absence of formatting or calculation errors in final delivery files.
• Client Collaboration & Technical Delivery – Work closely with product managers, engineers, and senior data scientists in a collaborative, software-development style – gather requirements, contributing to technical scoping, and participating in agile ceremonies and code reviews.
• Cross-Functional Initiative Support - Participate actively in company-wide product development initiatives, research-on-research experiments, and technical thought leadership groups. The Junior Data Scientist collaborates across data operations, cloud engineering, product, and engineering departments to support the trial of new
  analytical and engineering methodologies. This cross-pollination of ideas ensures the product data science team remains at the forefront of marketing science and technical innovations. Engagement in these initiatives is demonstrated by active participation in internal sharing sessions and support for pilot projects.

Qualifications:

• We genuinely don’t mind what is written on your certificate. While we would love you to have a formal qualification in any discipline that builds strong analytical and problem-solving skills, we primarily care that you're clever, rigorous, and can do the job. Equivalent practical experience - whether self-taught, through bootcamps, open-source contributions, a strong portfolio, or prior industry work - is just as welcome as a formal degree.
• A successful applicant must demonstrate solid programming ability (Python and ideally SQL) and an interest in writing good, maintainable software - not just scripts.
• A successful applicant must further demonstrate a genuine appetite for technical depth, mathematical rigour, and continuous learning.

Who We Are:
MarketCast measures what moves people. Powered by AI, trained on decades of verified consumer response data, and backed by proprietary technology, MarketCast is the marketing effectiveness partner for the world's most ambitious brands, connecting emotional resonance to real-world business outcomes across advertising, sponsorships, content, brand health, and advanced analytics. With category-deep expertise spanning sports, entertainment, travel, automotive, and consumer brands, our team of
seasoned industry strategists brings unmatched human intelligence to every engagement, turning complex data into decisive action so brands know exactly what's working, why it's working, and what to do next.

At MarketCast, we don't just accept difference - we embrace it, support it, and thrive on it for the benefit of our global culture and success. MarketCast is proud to be an equal opportunity workplace. We are committed to equal employment opportunity regardless of race, colour, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status. We also consider qualified applicants regardless of criminal histories, consistent with legal requirements. If you have a disability or special need that requires accommodation, please let us know. Check us out on LinkedIn and at: www.marketcast.com

Our Values:
Move The Needle
We turn insight into action and action into impact, acting with urgency and intention at every level, anticipating what's needed, executing with discipline, and driving outcomes that are measured and meaningful.

Client Success is Our Scoreboard
We win when our clients win. Delivering scaled, tech-enabled solutions that drive measurable impact and value to build lasting partnerships.

Grow Every Day
Expertise is earned continuously by investing in our craft, our colleagues, and our company.

Own It
Take responsibility for outcomes, not just outputs.

Benefits:

• Free movie tickets!
• 29 days annual leave PLUS Bank Holidays
• Flextime with core hours between 10am and 3pm
• 2 days’ work from home per week
• 4% match pension scheme
• Enhanced maternity pay
• Regular social events in both UK locations
• Professional growth and career development including LinkedIn Learning

In addition to your salary, MarketCast believes in providing a competitive total rewards package for its employees. All benefits are subject to eligibility requirements, and the terms of our official plan may be modified or amended from time to time.

GENERAL DATA PROTECTION REGULATION (UK GDPR) NOTICE: The organisation collects and processes personal data relating to its applicants, employees and former employees to manage pre-employment and employment relationships and post-employment obligations. The organisation is committed to being transparent about how it collects and uses that data and to meeting its data protection obligations. For further information on the information we collect, how it’s used, and how it's protected, please contact the MarketCast UK HR Team.