William Dennis

PhD Researcher (PrO-AI CDT), University of Bristol
4+ years of industry experience across energy, finance, and medical devices.

Experience

Honorary Research Associate in Machine Learning

University of Bristol · Bristol, UK
Oct 2024 – Present
  • Released and active owner of an open-source fault-injection framework used within the department for the wider research community.
  • Actively exchanged knowledge with industry stakeholders on fault-tolerance methods for AI systems.

Research Intern

University of Bristol x National University of Singapore · Bristol
Jun 2026 – Jul 2026
  • Researched reinforcement learning methods for health behaviour change, supervised by Dr. Mengyan Zhang (University of Bristol) and Swapnil Mishra (National University of Singapore).
  • Sole developer of rl-health-interventions: a config-first simulator for Just-In-Time Adaptive Interventions.

Energy Modeller

Aurora Energy Research · Oxford, UK
Oct 2024 – Jun 2026
  • Forecasted the impact of AI datacentre demand and collaborated with clients interested in SMRs.
  • Applied modelling methods using convex optimisation, linear programming, and maximum likelihood estimation with a core focus on explainability, robustness and interpretability.
  • Researched and presented a business case for reinforcement learning to improve energy pricing.
  • Led modelling of the Polish, Czech and Slovak energy market models, tailoring foundational models to regional needs and building internal toolkits across Europe with Streamlit and SQL.
  • Applied best software engineering practices, including test-driven development, Git version control, and agile/scrum workflows.

Data Scientist

JPMorgan · Bristol, UK
Feb 2024 – Jul 2024
  • Led a team of 4 data scientists to produce in-house quant level research into the development of trading signals derived from millisecond level limit-order-book data.
  • Built tooling for my team to parse millions of rows of raw text data on local machines using JIT.
  • Created baseline models using ARIMA, RNNs and LSTMs on level-1 data.
  • Engineered 50+ features derived from cleaned up level-2 limit order book data.

Signal Processing Engineer

Milbotix · Bristol Robotics Lab, UK
Feb 2024 – Oct 2024
  • Developed a two-stage machine learning pipeline optimised for use on embedded devices using accelerometer filtering and novel Fourier features.
  • Reduced pipeline latency from minutes to seconds via an accelerometer-based filtering layer and JIT compilation.
  • Achieved an error rate of <3bpm, allowing the device to be medical grade.
  • Extended to lead validation for medical-grade labelling.

Intern Hedging Analyst (Risk Team)

Ocean Partners · Maidenhead, UK
Jul 2021 – Jul 2022
  • Mitigated £250m of physical commodity transactions via the London Metal Exchange.
  • Maintained a strong relationship with banks and brokers using responsive and professional communication.
  • Automated a data analysis task for clearing transactions, saving 60 minutes of manual labour daily.

Education

University of Bristol

PhD, PrO-AI CDT
Sep 2026 – Present
Doctoral Researcher
  • Funded doctoral place under Professor Peter Flach, Department of Computer Science.

University of Bristol

MSc Data Science
Sep 2023 – Sep 2024
Distinction (Top 3 of cohort)
  • Researched theory of neural network generalisation: grokking, double descent, Lipschitz continuity.
  • Deployed distributed cloud architectures on AWS (DynamoDB, SQS, SNS, S3, EC2).
  • Studied technology ethics, legal awareness (GDPR), NLP, and the history of technological innovation.
  • Produced a Tableau report analysing migration patterns of UK residents aged 20-25.
  • Active member of Google Developer Student Club; Quantitative Analyst, Bristol Trading Society.

University of Bath

BSc (Hons) Mathematical Sciences
Sep 2019 – Jul 2023
Scientific Computing (84%) and Machine Learning (91%)
  • Built websites in Python to support startups in SETsquared using Django.
  • 2019/2020 poker society winner.

Research & Publications

I study how machine learning systems fail under real-world stress, and how evaluation practices shape what we can claim about them. My work spans fault injection and robustness in neural networks, reproducible benchmarking of ML and LLM systems, and applied reinforcement learning for health behaviour change. I am interested in practice-oriented methods that make reliability claims testable outside the lab.

Publications

William Dennis and James Pope

Lecture Notes in Computer Science, Vol. 16517 (LNAI) Jun 2026

William Dennis and James Pope

ICAART 2025 (17th International Conference on Agents and Artificial Intelligence) Feb 2025

Steer, Z., Venkatesh, P. T., Mejia-Mejia, E., Dennis, W. W., Ogundele, P. A., Brooking, A., & Eimontaite, I.

Alzheimer's & Dementia, 20(S8), e095065 2025

Research Projects

Longitudinal Evaluation of a Coding-Agent Harness

2026

Longitudinal evaluation of a coding-agent harness over a multi-month horizon with the model fixed, using a custom research runner, pinned tasks, repeated trials, and cost and provenance controls.

LLMEvaluationBenchmarking

SLM Bias Testing

2026

Benchmarking framework for bias in small language models, covering StereoSet, WinoBias, CV screening, and demographic output-length disparity. Evaluates how bias changes across model size, family, and release date.

NLPBiasBenchmarking

Reinforcement Learning for Health Behaviour Change

2026

Config-first simulation environment for Just-in-Time Adaptive Interventions (JITAIs) with bandit and RL baselines, heterogeneous user models, and an LLM user simulator.

Reinforcement LearningHealthcareSimulation

Multi-Agent RL for Energy Markets

2025

Exploratory multi-agent reinforcement learning framework with PPO agents and a Gymnasium-compatible electricity-market bidding environment.

RLEnergyMARL

Robust ML in Harsh Environments

2025

A novel framework in Python with PyTorch for evaluating neural networks in harsh environments. Proposed two novel activation functions that proved more robust to SEE-related errors.

PyTorchResearchComputer Vision

Classification of Signal Quality from Ankle-Based PPG Signals

2024–2025

Research project with Milbotix developing novel time-series features and neural-network classifiers for ankle-based PPG signal-quality classification, evaluated with AUC and ROC metrics.

Signal ProcessingTime-SeriesMedical ML

Personal Projects

OpenFrontBench

2026

Open-source RTS agent benchmark built on a pinned OpenFrontIO engine, with scripted and MCP-based agents, replay verification, and analytical policy baselines.

AgentsBenchmarkingGame AI

Moonboard-Analysis

2025-2026

ML benchmarking framework for climbing route prediction. Designed a reproducible evaluation protocol with 5-fold retrain-per-fold cross-validation, tested 8+ model architectures (MLP, LSTM, CNN, Transformer, Ridge, Perceptron), and established a non-tree leaderboard. Built dataset augmentation pipeline with hold-swap tokenisation and identified/patched data leakage bugs.

PyTorchMLBenchmarkingClimbing

Chess AI

2022–2026

Three-part guide series on building chess bots, plus a CNN-based chess agent for automated play, covering minimax search, GUI tooling, and end-to-end evaluation.

EducationGame AIComputer Vision

RL Trader

2023

Reinforcement-learning trading agent using linear features.

RLFinance

Evolutionary Snake AI

2021

Built an evolutionary learning algorithm from scratch to play snake at a human like level using neural networks.

Genetic AlgorithmsNeural Networks

Steam Market Trading

2020-2023

Averaged 366% yearly ROI trading on the Steam marketplace web scraping data.

Web ScrapingAutomation

Technical Skills

Languages

Python (10+ years)SQLC#RMATLABHaskellTypeScriptGAMS

Libraries & Frameworks

PyTorchTensorFlowScikit-learnPandasNumPyOpenCVStreamlitDjango

Cloud & Tools

AWSGoogle CloudDockerGitJIRAAgile