Senior Data Scientist (Contract · London)

We are looking for a Senior Data Scientist to join a seed-stage AI project on a full-time contract basis (2-3 months, with possible extension or transition to a permanent role). The project is building a computable model of the global chemicals and materials economy.

This is a hands-on role - you will be setting the standard, not following one.

Location: London, hybrid (priority)

Start: ASAP

Format: Contract, full-time, 2-3 months

Your responsibilities will include:

• Profile and explore complex real-world industrial datasets - chemical plants, supply chains, material grades
• Build baselines, then define evaluation sets and metrics before modelling
• Ship classifiers and matching/inference models with measured error rates and written error analyses
• Use LLMs where they genuinely belong - extraction, constrained labelling, code generation - with proper evals, never open-loop guessing
• Document model decisions, failure modes, and validation approaches clearly

What we expect from you:

• Proven track record of shipping models to production where being wrong had real consequences - and ability to explain exactly how they were validated
• Strong Python - pandas, scikit-learn, solid statistical instincts
• Ability to define evaluation frameworks and metrics independently, not just implement someone else's
• An independent operator mindset - comfortable setting standards in an early-stage environment
• Experience building LLM pipelines with real evaluation harnesses is a strong plus
• No chemistry background needed - domain expertise is provided by the team

Soft skills / Mindset:

• Rigorous - defines what "good enough" means before building, not after
• Communicates clearly - can explain model decisions, tradeoffs, and failure modes to a non-technical audience
• Fast - comfortable with startup pace and ambiguity
• Honest about uncertainty - flags unknowns early rather than papering over them

What We Offer:

• Work at a Top-employer company (according to DOU 2025)
• A strong culture built on empathy, trust, openness, and real care for employees
• Paid vacation and sick leave
• Team events and regular team-building activities