Work

Current

State–Time Geometry

Development of a geometric model for the semantics and structure of computational execution, including failure and recovery. The approach originated decades ago and is now grounded in established geometric frameworks and related to existing models in computer science.

SST (Swiss Software Tool)

Development of simple, declarative tooling for runtime and infrastructure development. Current work includes a new virtual-machine runner and a Dockerfile-based build system.

git-zfs

Exploration of a git-based approach to managing filesystem subtrees and storage workflows. The system addresses persistent problems in scientific and AI computing, including ephemeral cluster configuration and storage hierarchy management.

Current Affiliations

• Visiting Professor of Physics, Oxford University
• Visiting Research Fellow in Mathematics, Oxford University
• Wyliot Fellow, Merton College, Oxford
• Visiting Professor of Computer Science, Waseda University

Past Work

Advising Research Programs

• Member of a committee (c. 2011) defining the focus and structure of the European Horizon 2020 research programme.
• Advisor to the SKA scientific data-processing effort on programming models, frontier micro-architecture, software processes, and connections between rough-path theory and telescope correlation pipelines; facilitated collaboration between industry and academia in Cambridge.
• Advisor to Heidelberg University’s electronics engineering department in preparation for participation in the 2018 European Chips Programme.
• Contributor to curriculum development and research seminars in machine learning and physics at Oxford University.
• Founder and chair of the Exascale I/O Working Group (early–mid 2010s), guiding the storage community in evaluating alternative large-scale architectures.

Software Systems

• Creator of the Lustre parallel file system at Cluster File Systems, guided by U.S. Department of Energy requirements; Lustre remains widely deployed more than 25 years after its introduction.
• Ported Coda to Linux and created the Intermezzo filesystem; both were integrated into the Linux kernel. Contributed to performance, scalability, and recovery design in ext4.
• Designer of the Colibri filesystem, a successor to Lustre; while not fully implemented, the work led to a subsequent startup acquisition.
• Research on parallel computing inspired by Karmarkar’s work; introduction of persistent transactional memory in Haskell (with Simon Peyton-Jones and students).
• Early work with Francis Crick and Christof Koch on computational models of consciousness using neural networks (1990s).

Mathematics

• Renewed focus on mathematics from 2015 onward.
• DPhil research on gauge theory for magnetic monopoles and three-manifolds, supervised by Sir Michael Atiyah (Oxford).
• Work in mathematical physics, topology, differential and algebraic geometry, and Fourier integral operators, including collaborations with Donaldson, Duistermaat, and others.
• Ongoing interest in numerical methods.