Data Scientist 💻

Simon
Thornewill von Essen

Ambiguous Questions ➡️ Decisions A/B Testing 📊 Causal Inference ⚗️ Bayesian Modelling 🎲

7+ years experience  ·  London, UK

Bottom line, Up-front; I help companies that genuinely want to understand their customers and how to improve their products.

Businesses rarely have clean data, clear hypotheses, or full understanding of their problem space. With deep experience in causal inference, Bayesian modelling, and experimental design, I help navigate these complexities—understanding not just what is happening, but why and what to do about it.

I've blocked £5M/year in fraud risk, cut delivery times by ~3 seconds per order, and saved ~£500K/year through targeted experiments—across Fraud Detection, Logistics, Restaurant Operations, and Marketing.

I work across the full lifecycle: framing ambiguous problems with stakeholders, delivering end-to-end solutions, and mentoring teams along the way.

See my full experience →

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Programming & Data Engineering

Python R SQL Numpy Pandas PyMC Airflow ETL Data Pipelines Model Deployment

ML & Statistics

Machine Learning Bayesian Statistics Causal Inference A/B Testing Experiment Design Regression Simulation Optimisation

Visualisation & Data Stack

Looker Tableau Dashboarding Data Storytelling

AI & LLM Tooling

LLM Engineering LLM Integration Prompt Engineering AI-Assisted Development Cursor Claude Code

Professional

Stakeholder Management Mentoring Communication Cross-Org Collaboration Product Thinking Project Scoping
Go / Baduk Guitar Fitness Obsidian