I am Ian Reppel (a.k.a. Hellström). Right now, I work as a Principal Product Manager at Mirza, where I help families access life-changing public benefits they are eligible for but often go without. I have built platforms serving hundreds of millions of customers at Spotify, Nubank, Bosch, Jua, and D2iQ, including one with an annual impact of $240 million. My work on machine learning predates “AI” meaning generative AI: modelling, training, inference at hyperscale, edge ML, and end-to-end platforms. I hold a PhD in theoretical physics. The essays on this site are how I think.
Get in touch if you need someone to solve a problem that requires novel thinking or where failure is not an option.
All opinions expressed here or elsewhere are those of the author, and they do not necessarily represent the sentiments or opinions of any employer, affiliate, client, or investor.
Awards
- Special mention for The Quantum Cradle: Prebiotic Minerals as Quantum Search Engines for Life at the 2025 FQxI Essay Competition, out of nearly 100 submissions
- Honourable mention for The Mind as a City: A Systems View of Consciousness at the 2025 Berggruen Prize Essay Competition, out of more than 3,000 submissions
- Marie Curie ESR Fellowship in The Astrodynamics Network (2007–2010)
Projects
- Crossfire: a multi-agent adversarial refinement orchestrator that pits LLMs against each other to generate, critique, and synthesize better output (a.k.a. Ralph on ‘roids)
- Zoose: JupyterLab Docker images with flavours for quantum computing (IBM Qiskit ecosystem), PyTorch, graph analytics, and geospatial analysis, runnable in-browser via GitHub Codespaces
- Oracle SQL & PL/SQL Optimization for Developers: 100+ pages on writing efficient Oracle database code
Guest Posts
- D2iQ: AI Chihuahua! Build or Buy (2021)
- D2iQ: AI Chihuahua! Why Machine Learning is Dogged by Failure and Delays (2021)
- KDnuggets: A Tour of End-to-End Machine Learning Platforms (2020)
- D2iQ: Kaptain: The Enterprise Machine Learning Platform (2020)
- Datafloq: The Need for Industrial Data Science (2016)
- Datafloq: What is the Value of a Megabyte? (2016)
Talks
- Sorry, Batman is Busy! How to Succeed in ML without the Batphone (Data Summit Connect, May 2021)
- Machine Learning Platforms in the Wild: A Safari (Scaling Continuous Delivery, February 2021)
- AI Chihuahua: Why Machine Learning is Dogged by Failure and Delays (Cloud Native Summit, October 2020)
Publications
- Technology Diffusion and Its Effects on Social Inequalities (with Manuela Magalhães), Journal of Macroeconomics (2013)
- Numerics of Spacecraft Dynamics, PhD thesis, University of Turku (2011)
- Creating Variational Integrators with a Computer Algebra System, Albanian Journal of Mathematics (2010)
- VarInt: Variational Integrator Design with Maple, ACM Communications in Computer Algebra (2010)
- Explicit Algorithmic Regularization in the Few-Body Problem for Velocity-Dependent Perturbations (with Seppo Mikkola), Celestial Mechanics and Dynamical Astronomy (2010)
- Universal Formulation of Quasi-Keplerian Motion, and Its Applications (with Seppo Mikkola), New Astronomy (2009)
- Satellite Attitude Dynamics and Estimation with the Implicit Midpoint Method (with Seppo Mikkola), New Astronomy (2009)