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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
Email 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

  • 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
  • 2012 – 2013
    MSci — Physics
    King's College London, London, UK
    • Fields: Physics · Mathematics
  • 2009 – 2012
    BSc — Physics
    King's College London, London, UK
    • Fields: Physics · Mathematics

Experience

  • 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
  • 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)
  • 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
  • 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
  • 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
  • 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
  • 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

  • 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
  • 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
  • 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
  • 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

  • 2026
    • Institute of Physics Machine Learning: Science and Technology Outstanding Reviewer Award
  • 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)
  • 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

  • 2023 – present
    ATLAS National Analysis Facility (NAF) Representative — Germany
  • 2021 – present
    Leader, Machine Learning Assisted Monte Carlo Uncertainties forum — ATLAS
  • 2021 – 2025
    Higgs Machine Learning Expert/Liaison & Paper Reviewer — ATLAS
  • 2021 – 2022
    ATLAS Physics Modelling (Weak Vector Boson) & Monte Carlo Simulation Convener
  • 2020 – 2024
    ATLAS Hbb Physics Modelling & Monte Carlo Simulation Expert/Contact
  • 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

  • 6.2026
    Helmholtz AI Conference 2026
    • Organisation Committee Member — haicon.cc
  • 6.2025
    Helmholtz AI Conference 2025
  • 10.2023
    2nd ATLAS Higgs Workshop 2023
    • Machine Learning Program Organiser — Indico
  • 6.2023
    Helmholtz AI Conference 2023
    • Abstract Reviewer; S-03b Applied AI Session Convener
  • 5.2019
    ATLAS H→bb Workshop
    • Monte Carlo Physics Simulation Program Organiser

Selected Talks

  • 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

  • 2026
    Terascale Statistics School — Machine Learning lecture series
  • 2025
    DESY Summer School — Machine Learning lecture series
  • 2024 – present
    Yearly ATLAS Germany ML lecture series (~100 BSc/MSc/PhD/postdocs)
    • Interactive tutorials on machine learning for HEP data analyses
  • 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

Skills

  • 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)
  • Programming
    • Python, C++, Bash (10+ yrs)
    • SQL / Kuzu / Neo4j (2+ yrs)
    • Fortran (2 yrs), CUDA (1+ yr), Rust (<1 yr)
  • ML tools
    • PyTorch, TensorFlow (7+ yrs)
    • ONNX, Hugging Face (5+ yrs)
    • JAX (2 yrs)
    • LangChain / LangGraph, MLflow (1+ yr)
  • Data science & engineering
    • Scikit-learn, NumPy, Pandas, ROOT (7+ yrs)
    • SciPy, matplotlib, seaborn (5+ yrs)
    • DASK (2+ yrs); Luigi, OmegaConf, Hydra, OpenCV (1+ yr)
  • 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.