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Curriculum vitae of Dr Stephen P. W. Jiggins — machine learning researcher, physicist, and AI engineer.
General Information
| Full Name | Dr Stephen P. W. Jiggins |
| Roles | Machine Learning Researcher · Physicist (HEP) · Data Scientist · AI Engineer |
| Affiliation | DESY / Helmholtz AI / ATLAS · useblocks GmbH |
| Location | Hamburg, Germany |
| stephen.pw.jiggins@gmail.com | |
| Phone | (+44) 7732 372 459 |
| GitHub | github.com/sjiggins |
| Languages | English (native), German (A2/B1), French (A1/A2) |
Biography
- Machine learning researcher and software developer with 10+ years bridging ML research and scientific applications across particle physics, nuclear, and medical domains.
- Extensive experience building and maintaining research software infrastructure at scale (exa-byte HPC/HTC systems), and leading cross-institutional ML/software projects involving small (~10) to large (~100s) teams.
- Proven track record sourcing funds from government and non-government sources. Specialties include Monte Carlo simulation, generative AI (diffusion/flow matching), neural simulation-based inference, probabilistic machine learning, agentic systems, and scientific writing.
Education
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2013 – 2017 PhD — High Energy Physics
University College London, London, UK - Fields: Physics · Statistics · Machine Learning · Data Science
- Doctoral research with ATLAS at CERN on peta-byte scale data analysis and Monte Carlo physics modelling
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2012 – 2013 MSci — Physics
King's College London, London, UK - Fields: Physics · Mathematics
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2009 – 2012 BSc — Physics
King's College London, London, UK - Fields: Physics · Mathematics
Experience
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01/2025 – present Principal Investigator — Machine Learning Lead
Helmholtz AI (fund) — Hamburg, Germany - ML lead of NEEDLE (NEural-basEd Diffusion Likelihood Estimations): diffusion/flow-matching neural simulation-based inference toolkit for distributed HPC, aimed at cross-sector Helmholtz adoption (release target ~2027)
- Authored and obtained a €0.5M Helmholtz AI grant to fund NEEDLE software development
- Built Luigi-based DAG orchestration for ML training, evaluation, experimentation, and versioning on HPC/HTC (≥50,000 cores)
- Developed complex-valued flow-matching models for signed/quasiprobabilistic paths, and neural density-ratio evaluation ~10× faster than conventional ODE/SDE solvers
- Manage an ~10-person international team of data scientists, ML engineers, and scientists across institutes
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08/2025 – present Lead AI Engineer
useblocks GmbH — Munich, Germany - Lead AI engineer for automotive code–requirements traceability (Tier-1 / OEM)
- Embedded safety-critical documents into Qwen/Ollama LLMs as hypernetworks with RAG, improving safety-critical query accuracy (~80%), reducing token usage, and cutting response time (>90%)
- Designed LangChain/LangGraph agentic system translating natural language to Cypher for ubTrace (Kuzu, Neo4j, Memgraph)
- Built as-Code MCP architecture for AI agents, reducing LLM token usage ~70% and latency ~40%
- Built scalable infra for parallel production/development AI pipelines (ubCode / ubTrace / ubc)
- Maintainer of the COVESA Generative AI working group (MCP tooling and A2A patterns for automotive)
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2022 – present Research Fellow — Machine Learning Researcher
DESY — Hamburg, Germany - Generative AI (diffusion/flow matching), computer vision, and probabilistic ML for Monte Carlo physics simulations
- Diffusion/flow models to emulate particle interactions with 2D/3D silicon sensors (~1M sensors) for LHC detectors; ONNX deployment path toward the WLCG (~1.5M cores)
- Built Open3D/ML point-cloud visualisation combining 3D meshes and point clouds for multi-modal diffusion
- Funded international collaboration with the Croatian Science Foundation via EU Mobility and Resilience Plan grants (~€16k)
- Quasi-probabilistic ML classifiers for quantum physics (and related signed-weight settings); HiDA grant (~€20k) with American Family Insurance Data Science Institute, Wisconsin–Madison
- System architecture engineer for the German National Analysis Facility (NAF) HPC infrastructure planning
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2021 – 2022 Postdoctoral Research Associate — HEP & Machine Learning
University of Edinburgh — Edinburgh, UK (assigned to CERN) - Peta-byte scale analyses and computational optimisation for synthetic data generation
- Project leader of a 20–40 person Monte Carlo / synthetic-data team on the WLCG
- Deployed CARL-torch to reduce exa-byte-scale synthetic-data disk usage by up to ~50%
- Built C++/Python SPEC-2006 benchmarking for ATLAS simulation; adaptive biasing cut Monte Carlo generation time by ~50%
- Developed GNN embedding models for detector image feature clustering
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2018 – 2022 Postdoctoral Researcher — HEP & Machine Learning
Universität Freiburg — Freiburg im Breisgau, Germany - Co-author of open-source CARL-torch (PyTorch likelihood-ratio estimator, CPU & GPU)
- Co-discoverer of key Higgs decay mode: Phys. Lett. B 786 (2018) 59 (observation of H→bb̅ and VH)
- BDT likelihood-ratio importance sampling increasing Monte Carlo statistical precision by >2×
- Core developer of CxAOD ETL analysis software used by ~300–500 personnel across CERN (still in use)
- Project leader of a 5–10 person Monte Carlo simulation team; supervision/teaching of PhD/MSc/BSc students
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2013 – 2017 PhD Research Associate — Data Science & Physics
CERN / University College London — Geneva, Switzerland - Core developer of multi-language (C++/Python/Bash) peta-byte ETL analysis software used by 300–500 scientists on the WLCG
- Monte Carlo integrator for heavy-flavour processes; BDT classifiers for hypothesis testing on LHC data
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06/2012 – 09/2012 Research Associate — Medical Physics / Computer Vision
King's College London — London, UK - C/C++ simulation of single-photon counting with electron-bombarded CCDs
- Centroiding algorithms for sub-pixel accuracy (~25% improvement in time/position resolution) for fluorescence lifetime imaging
Successful Grant Applications
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April 2026 – present Calibrated Density Ratio Estimation for Diffusion Models (PMF-GOOUT-2026-03)
Croatian Science Foundation (HRZZ) exchange fund - Host and PI of a 6-month project on fast neural likelihood evaluation for diffusion models in LHC physics
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Dec. 2024 – present NEEDLE — Neural-based Diffusion Likelihood-free Estimations
Helmholtz AI 2023 - Author and PI of a 3-year collaboration (ATLAS DESY & CMS KIT) on neural likelihood-free inference for HEP
- €0.5M Helmholtz AI funding
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Dec. 2024 – Jun. 2025 Neural Likelihood-free Inference in Peta-byte Data Analyses (MOBDOK-2023)
Croatian Science Foundation / EU Recovery and Resilience Plans - Collaboration with University of Zagreb on neural likelihood-free inference for ATLAS & ALICE
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Dec. 2023 – Jun. 2024 Interpreting Negative Probabilities in Supervised Learning
Helmholtz Information and Data Science Academy (HiDA) - Author, host, and PI of a 3-month HiDA project on quasiprobabilistic likelihood-ratio estimation
Academic Awards
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2026 - Institute of Physics Machine Learning: Science and Technology Outstanding Reviewer Award
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2013 - SET Award Finalist — Institute of Physics (1 of 3 undergraduate physics projects nationally)
- James Clerk Maxwell Prize — King's College London (excellence in 4th-year thesis)
- Layton Science Research Award — King's College London
- Wheatstone Prize — King's College London (highest 4th-year grade)
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2012 - Nelkon Prize — King's College London (highest 3rd-year / BSc-equivalent grade)
- Leica Microsystems Prize — King's College London (highest 2nd-year laboratory Physics)
Community Leadership
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2023 – present ATLAS National Analysis Facility (NAF) Representative — Germany
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2021 – present Leader, Machine Learning Assisted Monte Carlo Uncertainties forum — ATLAS
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2021 – 2025 Higgs Machine Learning Expert/Liaison & Paper Reviewer — ATLAS
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2021 – 2022 ATLAS Physics Modelling (Weak Vector Boson) & Monte Carlo Simulation Convener
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2020 – 2024 ATLAS Hbb Physics Modelling & Monte Carlo Simulation Expert/Contact
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2018 – 2021 ATLAS VH(bb) Analysis leadership member
Journal Editorial Roles
- 2024 – present: Machine Learning: Science and Technology (IoP) — Certified Review Editor
- 2024 – present: Frontiers in Big Data & AI in High Energy Physics — Review Editor
Conference / Workshop Organisation
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6.2026 Helmholtz AI Conference 2026
- Organisation Committee Member — haicon.cc
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6.2025 Helmholtz AI Conference 2025
- Abstract Reviewer — haicon.cc
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10.2023 2nd ATLAS Higgs Workshop 2023
- Machine Learning Program Organiser — Indico
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6.2023 Helmholtz AI Conference 2023
- Abstract Reviewer; S-03b Applied AI Session Convener
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5.2019 ATLAS H→bb Workshop
- Monte Carlo Physics Simulation Program Organiser
Selected Talks
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6.2026 NEEDLE — Columnar Workflow Orchestrator for Large-Scale Neural SBI in HEP
CHEP 2026 -
9.2025 Neural Quasiprobabilistic Likelihood Ratio Estimation with Negatively Weighted Data
ACAT 2025 -
6.2024 Quasi-probabilistic LR estimation; DeGeSim diffusion density mappers
Helmholtz AI Conference (HAICON24) -
11.2023 DeGeSim — Conditional DDPMs as Multi-Dimensional Density Mappers
ML4Jets 2023 -
6.2023 ATLAS Higgs Group Machine Learning Overview
2nd ATLAS Higgs Workshop (Tokyo) -
7.2022 Novel experimental techniques for the Higgs sector
ICHEP 2022 -
6.202 Higgs measurements in 3rd-generation decay channels (ATLAS & CMS)
LHCP 2020
Lectures & Teaching
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2026 Terascale Statistics School — Machine Learning lecture series
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2025 DESY Summer School — Machine Learning lecture series
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2024 – present Yearly ATLAS Germany ML lecture series (~100 BSc/MSc/PhD/postdocs)
- Interactive tutorials on machine learning for HEP data analyses
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2017 – 2021 Laboratory teaching (FP1 & FP2) — Universität Freiburg
- Designed and built 3 experiments; entrance exams, report grading, and scientific writing feedback for BSc/MSc students
Academic Student Supervision
- Supervised 7 PhD students (6 defended; 1 ongoing), plus DESY summer BSc/MSc students (11-week programme).
- 2024–2027: Stefan Katsarov, PhD Humboldt-Universität zu Berlin (ongoing)
- 2022–2024: Lars Ferencz, PhD Humboldt-Universität zu Berlin — associated Higgs with top quarks, H→bb̅ with ATLAS
- 2020–2022: Adrian Jimenez, PhD University of Valencia / IFIC — dark matter, vector-like top, AI anomaly detection
- 2020–2022: Lubos Vozdecky, PhD Queen Mary University — H→bb̅ cross section and deep learning for background modelling
- 2018–2022: Thomas Charman, PhD Queen Mary University — H→bb̅ and VH production with ATLAS at 13 TeV
- 2018–2019: Carlos Viguel Vergel Infante, PhD Iowa University — high-pT VH(bb) with Center-of-Mass tagger
- 2018–2021: Simona Gargiulo, PhD Freiburg — H→bb̅ observation/measurement and quasi-stable b-tagging
Software & Datasets
- S. Jiggins & M. Drnevich, Neural Quasiprobabilistic Likelihood Ratio Estimation Dataset, Zenodo (2025), doi:10.5281/zenodo.15102316
- S. Jiggins et al., carl-torch v2.2.1, Zenodo (2023), doi:10.5281/zenodo.10209681
Skills
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Domain expertise
- High Energy Physics (10+ yrs)
- Machine Learning Engineering (6+ yrs)
- Machine Learning Research (3–4 yrs)
- Distributed HPC (10+ yrs)
- Computer Vision (3+ yrs)
- AI Engineering (1+ yr)
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Programming
- Python, C++, Bash (10+ yrs)
- SQL / Kuzu / Neo4j (2+ yrs)
- Fortran (2 yrs), CUDA (1+ yr), Rust (<1 yr)
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ML tools
- PyTorch, TensorFlow (7+ yrs)
- ONNX, Hugging Face (5+ yrs)
- JAX (2 yrs)
- LangChain / LangGraph, MLflow (1+ yr)
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Data science & engineering
- Scikit-learn, NumPy, Pandas, ROOT (7+ yrs)
- SciPy, matplotlib, seaborn (5+ yrs)
- DASK (2+ yrs); Luigi, OmegaConf, Hydra, OpenCV (1+ yr)
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Software development toolkits
- OS: UNIX & Windows
- VCS: Git, SVN · Project management: JIRA
- Docs: LaTeX, Markdown, MkDocs, Sphinx
- Containers: Docker, Singularity/Apptainer
- Packaging: Astral uv (Python), npm (Node.js)
References
- Available on request.