Senior Data Scientist in London

At GoodFit, we help our customers unlock their next stages of growth with highly actionable and relevant data. Without spending thousands of hours on manual research, B2B companies use GoodFit's data engine to identify their next opportunities, understand their customers, and generate demand. Our platform takes data from hundreds of sources across the internet and combines it into a real-time, constantly updated view of each opportunity our clients monitor. We process large volumes of data to do this and utilise best-in-class data technologies to deliver this at scale, robustly and efficiently.

We have a strong market opportunity and are working with many of the highest-growth B2B companies. To continue accelerating product development and expanding our AI capabilities, we are growing our Data team.

As a Senior Data Scientist at GoodFit, you will be responsible for designing, prototyping, and shipping customer-facing ML/AI features that create measurable product value. You will operate at the intersection of experimentation and production — partnering closely with Product, Design, and Engineering to explore new ML capabilities, validate them quickly, and help turn them into scalable product features.

We are looking for someone who is comfortable navigating ambiguity, framing problems independently, and moving from raw data to shipped product features. Your ability to combine strong modelling fundamentals with product thinking will be key to our success.

You will:

• Design and develop ML models (e.g., classification, ranking, scoring) that power customer-facing features
• Use SQL and Python (pandas, scikit-learn) to analyse product data and identify opportunities
• Rapidly prototype new AI/ML-driven product ideas in collaboration with Product and Design
• Define hypotheses, evaluate model performance, and iterate quickly
• Collaborate with Engineering to productionise validated models
• Improve automation, personalisation, and predictive capabilities within the product
• Ensure models are measurable, interpretable, and aligned with user value
• Assess and validate internal and external data sources used in ML features
• Evaluate signal quality, bias, completeness, and reliability
• Define metrics and checks to ensure data is fit for customer-facing use
• Move from ambiguous problem to prototype to shipped feature with strong ownership

We would love to hear from you if you have:

• 5+ years of professional experience in data science or applied ML
• Strong SQL skills and confidence working directly with product data
• Strong Python experience for modelling (pandas, scikit-learn)
• Solid understanding of statistics and model evaluation techniques
• Experience shipping ML-powered features in production
• A product-oriented mindset and comfort working cross-functionally
• Strong communication skills and the ability to explain complex concepts clearly
• Experience working in a startup environment or high-growth company

Bonus:

• Experience shipping ML features in a B2B SaaS product
• Experience with LLM-based systems
• Experience with recommendation or ranking systems

Why you will love working at GoodFit:

• We are an early-stage startup with a strong growth trajectory. The work you do will have a direct and recognisable impact on our product and customers.
• We are a remote-first team, valuing long stretches of uninterrupted work over constant connectivity. We have an office near Old Street for those who prefer a hybrid working pattern. The entire team gets together for occasional planning and team meetings (max once per month).
• As a small team, you will work across multiple parts of the product and gain exposure to a wide range of technologies. You will have real ownership — from idea to shipped feature to happy customers — and the opportunity to work directly with experienced founders and product leaders.

Hiring process:

• Initial call
• Main technical interview
• Two project discussions (including experimentation and product improvement)
• Final stage interview with Product Manager and team member

Inclusion at GoodFit Ltd:

GoodFit Ltd. is an equal opportunity employer and we strongly encourage people of all ages, colour, lesbian, gay, bisexual, transgender, queer and non-binary people, veterans, parents, people with disabilities, and neurodivergent people to apply. We are happy to make any reasonable adjustments that will help you feel more confident throughout the process — please don’t hesitate to let us know how we can help.

Research shows that some candidates, particularly women and people from underrepresented groups, may hesitate to apply if they don’t meet every listed qualification. If this role excites you, we encourage you to apply even if your experience doesn’t align perfectly.