Senior Data Scientist - Generative AI in London

We’re on a mission to back the UK’s small businesses like no one else. Small businesses are the backbone of the economy, and we’re here to help them win. We’ve built a platform that uses clever data to get them the funding they need in minutes, not weeks.

At Funding Circle, we have the restless energy of a fintech start‑up with the stability of a public company. It’s a unique mix that gives Circlers the autonomy to take ownership and the scale to make an impact that truly counts. We’re a high‑performing team that chooses to lift each other up. We challenge, we champion, and we have each other’s backs – because we know that when we stand together, we move faster and build better. The impact is real: Last year alone, the businesses on our platform generated £7.2bn for the UK economy.

The role:

• Location: London (Hybrid) – 2 days in the office.
• Salary: Competitive Salary + Benefits.

You’ll make a real difference for our customers and your team from day one. We believe the fastest way to grow is by doing, so we give you the ownership to run with things and see real‑time results.

This is a hands‑on applied Data Science role. You will be architecting and building the algorithms behind our products. Your primary focus will be designing Agentic workflows, crafting tool definitions that allow LLMs to interact with our internal systems, and rigorously evaluating performance. While GenAI is the main focus of this role, traditional ML and algorithms will also be needed.

You will bridge the gap between experimental proof of concepts and production reality, establishing the evaluation frameworks and best practices that will eventually enable teams across the entire business to build their own GenAI products.

GenAI application creation: Design and implement the core logic for GenAI agents. You will create "tools" that the LLMs use to take action.

Evaluation and quality: Develop systematic evaluation of GenAI systems by building frameworks and methodologies. You will create evaluation datasets to measure accuracy, reliability, and tool-use, ensuring our models meet business standards before deployment.

Data analysis and Machine Learning: Analyse business data, identify opportunities for predictive modelling. Design, implement and test predictive ML algorithms.

Prototyping: Rapidly build functional application prototypes to demonstrate value to stakeholders and validate technical feasibility before full‑scale engineering begins.

Prompt engineering and logic: Optimise system prompts and reasoning chains to build customised GenAI applications.

Collaboration: Work closely with engineers and translate your prototypes into production services. Write code that is modular and readable so other teams can use and benefit from what you build. Work with non‑technical teams and build technology that solves their problems.

Responsible AI: Implement guardrails and adversarial testing to ensure our AI agents act ethically and securely, adhering to Funding Circle’s Responsible AI framework.

Mentoring and guidance: Support mid‑level team members, use your experience to unlock situations and provide clarity to the rest of the team.

What we’re looking for: We value deep expertise, but a growth mindset and good energy are what really make our team click. We’re a group that chooses to lift each other up and think smart every day.

We are looking for a Data Scientist with a strong engineering mindset. This is a Senior role, we are looking for someone with 5+ years experience and demonstrable deep expertise in the areas outlined below. You will be expected to be proficient from day one, but will also be given the opportunity to develop in areas of lower strength.

• Applied GenAI experience: Hands‑on experience building applications where LLMs interact with external data or APIs. You understand the nuances of tool use, and agentic concepts such as Retrieval Augmented Generation (RAG).
• Strong python skills: You write clean, reusable, and tested Python code. You are comfortable moving out of Jupyter Notebooks and into IDEs, and you can collaborate in a Git‑based workflow.
• Evaluation rigor: You have experience or a strong understanding of how to evaluate non‑deterministic and ML models systematically.
• Data fluency: Strong SQL and data manipulation skills. You can prepare data for R&D, you can build and evaluate predictive ML models.
• Curiosity: The AI landscape changes regularly. Roles and responsibilities are constantly evolving. You are excited to keep up to date with the latest advances in GenAI (e.g on agentic patterns, third party libraries and tools) and pragmatically apply them to business problems.
• Business empathy and problem solving: You excel at understanding the needs and pain points of business users, even when described in non‑technical terms. You are skilled at asking the right questions to get to the root of a problem and translating those requirements into effective technical solutions that deliver business value.

We’re building a place where everyone truly feels they belong. Even if your past experience doesn't align perfectly with every requirement, we'd still love to hear from you.

Why join us: We back you to build an incredible career. As a flexible‑first employer, we use a “best of both” approach. We’ll see you in our London office to collaborate – with barista coffee and subsidised Just Eat lunches on us!

• Flexibility: We provide a benefit allowance you can tailor to your own life and family.
• Health: This includes private medical and dental, health assessments, and access to a digital GP.
• Wealth: We offer life assurance, share schemes, and financial coaching.
• Development: You get a dedicated annual learning allowance to help you level up.
• Lifestyle: We have electric car and cycle‑to‑work schemes, plus season ticket loans.

We also have award‑winning parental leave policies. We're here to support you through the big life moments, from fertility treatments to new additions to the family.

Ready to join a mission that matters? We’d love to chat!