Principal Data Scientist

Principal Data Scientist | Series B | FinTech | SaaS | Scale-Up

Location: London Area, United Kingdom (Hybrid)

Salary: Up to £130,000 + Equity

Skills: Machine Learning | AI | Product ML | Deep Learning | Data Platforms

Our client is a rapidly scaling Series B FinTech SaaS business backed by leading VCs. Their platform is used by top financial institutions, digital banks, and emerging fintech innovators to power real-time risk intelligence, automate decisions, and deliver data-driven financial products at scale.

As they enter their next growth phase, they're expanding their Data Science function with a Principal Data Scientist who will set the technical direction, drive product-embedded AI, and help shape the future of data intelligence in financial services.

If you're excited by high ownership, greenfield innovation, and the chance to build category-defining AI in a fast-moving scale-up — this is that role.

ROLE: Principal Data Scientist

You'll be the most senior individual contributor within Data Science — leading technical strategy, architecture, and delivery of advanced ML systems across the platform. You'll work closely with Engineering, Product, and GTM teams to build scalable, production-grade AI that directly impacts customers and revenue.

This is a hands-on leadership role where you'll combine deep technical expertise with product thinking, experimentation, stakeholder influence, and team mentorship.

What You'll Be Responsible For

Technical Leadership & Strategy

• Define and own the Data Science roadmap across the Series B product suite.
• Architect scalable ML systems and end-to-end pipelines that integrate directly into the core SaaS platform.
• Evaluate emerging models, large language models (LLMs), and deep learning techniques to drive innovation in the FinTech domain.

Hands-On Modelling & Delivery

• Build, train, validate, and deploy ML solutions across risk modelling, anomaly detection, personalisation, optimisation, and predictive analytics.
• Lead experimentation cycles, champion best practices, and ensure models are production-ready.
• Partner with Machine Learning Engineers to scale models, optimise performance, and improve reliability.

Cross-Functional Product Impact

• Work with Product to define AI-driven features that enhance customer experience and create commercial value.
• Translate complex modelling outputs into actionable insights for internal and external stakeholders.
• Influence key strategic decisions in a hyper-growth environment.

Mentorship & Leadership

• Coach and mentor Senior and Mid-Level Data Scientists.
• Advocate for data science best practices across the organisation.
• Represent the team in technical discussions, customer workshops, and industry events.

What You'll Bring

Deep expertise in ML, statistical modelling, and modern AI techniques (supervised/unsupervised, time-series, Bayesian, deep learning).

Strong Python engineering skills — NumPy, Pandas, Scikit-Learn, plus PyTorch/TensorFlow.

Experience building scalable ML systems in production (ML Ops, CI/CD for ML, model optimisation).

Proven experience in a high-growth environment (startup/scale-up preferred).

Exceptional communication and stakeholder management skills — able to influence at all levels.

Strong understanding of financial services, risk, compliance, or decision-science is a bonus.

Passion for innovation, experimentation, and solving complex problems with data.

Why Join?

• High ownership role at the forefront of a scaling FinTech SaaS product.
• Direct impact on roadmap, technology choices, and the future of AI within the organisation.
• Equity in a fast-growing Series B business with strong backing and market momentum.
• Collaborative, engineering-led culture with room to innovate.

Apply now to become the driving force behind next-generation AI in FinTech.