
Exa-DI
Development and integration
Targeted project
Overview
The Exa-DI project is responsible for implementing the co-design and co-development process within NumPEx to develop a software stack that enables the productive use of exascale systems. Ensuring application productivity, portability, and longevity requires improving scientific software development methods by leveraging high-quality, maintained components (libraries, frameworks, and tools). This objective is supported by a national software development and engineering team (the Computational Data Team; CDT) comprising researchers and engineers with diverse expertise. The CDT includes a development team (CDT-DT) responsible for co-developing proxy/mini-apps based on algorithmic motifs shared across multiple Application Demonstrators (ADs), and a enabling team (CDT-ET) responsible for software packaging (e.g., Guix, Spack) and deployment. CDT activities are carried out using an Agile methodology based on an iterative process; this approach is driven by application needs and centers on shared algorithmic motifs (computation, communication) as well as common packaging and deployment methodologies and technologies.
Following co-design and co-development workshops focused on the algorithmic motifs identified during the joint analysis of the Application Demonstrators (ADs), 6 working groups (WGs) led by AD team members are now active. Their co-design and CDT engineering activities are hosted in a GitLab space named NumPEx-PC5. Additionally, a web infrastructure has been established to support software integration and collaboration platforms, notably consolidating all training modules.

Partners & Organisation
Consortium & Workpackages
Focus of the Exa-DI project is to accelerate development of exascale applications, by proposing “software development kits” – based on the methods, frameworks, libraries and software components developed in the other NumPEx projects Exa-MA, Exa-SofT, Exa-DoST & Exa-AToW – that provide sustainable, performant, and portable solutions to the most important computational and communication algorithmic motifs encountered in exascale Applications Demonstrators. These motifs are addressed through proxy-apps in an iterative co-design and co-development process together with the scientific & industrial application teams.
Workpackages
Exa-DI project consists in four work-packages:
The co-design principle
Co-design working groups are an attempt to bring together in a collaborative effort:
- —Applications Teams sharing similar exascale challenges,
- —Individual R&D teams from the other NumPEx projects (Exa-MA, Exa-SofT, Exa-DoST, Exa-AToW) who can provide partial solutions to these challenges,
- —The CDT (Computational Data Team) who is in charge of combining & integrating these partial solutions into curated "development kits" and "proxy-apps".
Working Groups
6 Working Groups led by an application team member and a referent Exa-DI:
Results to date
Results & Impact
Exa-DI activities:
- Co-analysis of ADs: 27 application demonstrators ranging a wide spectrum of computational science and engineering domains with an increasing number of hybrid AI/HPC computational workflow applications.
- Exa-DI workshops in 2023 Efficient PDEs discretisation @exascale and in 2024 Block-structured Adaptive Mesh Refinement @ exascale in 2024, Artificial Intelligence for HPC @exascale and Large-scale SKA processing workflows
Co-design and co-development Working Groups:
The WG1 is focused on specific cross-cutting algorithmic motifs and sub-motifs to improve the development of the next-generation high-order finite/spectral element software that enable a range of applications to run efficiently on exascale hardware through proxy and mini apps.
The objective of the WG2 is to develop a proxy-app demonstrating the generation/refinement of unstructured meshes with tens of billions of elements, and providing a set of services to discretize the physics-based partial differential operators and is in the process of creating, gathering and integrating the basic building blocks for this proxy-app.
In WG3, a “standardized” benchmark to evaluate and compare the performance of different AMR frameworks on various physics applications is being implemented, the challenge being to find some common solutions to the bottleneck of AMR codes .
For WG4, the challenge is to determine how to scale disctributed AI-HPC hybrid inverse and imaging workflowson large HPC infrastructure and then to identify/benchmark core ML building components to use and develop software bricks required to unlock/scale the use-cases.
Starting up: WG5 – AI-coupled HPC workflows – surrogate models @exascale and WG6 – AI-based large-scale processing workflows @exascale
Software packaging and deployment @exascale
- Strengthen and support adoption of meta build software technologies: Spack, Guix-HPC
- Develop collaborations with HPC national and regional facilities to support Spack and Guix-HPC
- Develop training materials/webinars / Hackathons on Spack and Guix-HPC and NumPeX Software catalog
- Develop and foster adoption of NumPeX software guidelines
- Foster CI and performance assessment methodologies
Exa-DI software production
Highlights
Highlight
Facilitating the deployment of HPC applications on Exascale supercomputers with Package Managers
The installation, portability, and reproducibility of parallel applications on large computing platforms have become increasingly challenging due to growing software complexity, extensive dependencies (e.g., AI frameworks), and heterogeneous hardware architectures. Current approaches based on modules employed on most supercomputers are reaching their limits, resulting in time-consuming tasks for both support teams and users. Modern software package managers are enabling a new paradigm where users can directly manage the installation of their software and dependencies.
As part of NumPEx software integration efforts, Exa-DI is advocating that user should leverage modern package managers to gain direct and fine grain control on their software stack, with a strong focus on Guix and Spack. In this context, a series of training and support events focusing on Guix, Spack, and the specifics of software deployment on supercomputers have therefore been organized and given by the Exa-DI Work Package 3. Since 2025, 7 NumPEx Tutorial Spack and Guix for beginner and advanced were delivered and 200 people were trained.
Switching to new ways of deploying software takes time. Exa-DI is always working to help users by offering training and support, packaging software, improving tools, and partnering with supercomputing centres to make the user experience better. The ambition is to have all NUMPEX-related libraries packaged with Guix and Spack, make Guix/Spack-based deployment part of every developer’s arsenal, and work with computing centers to make Guix/Spack-based user-level software deployment as frictionless as possible.
For more information:
Highlight
Toward Exascale: scaling AI-based inverse problems workflows at scale across multiple nodes and GPUs with a simple API.
- Research Goal: Develop large-scale AI-based inverse solvers and reference benchmarks for applications like CT, Cryo-ET, and Radio-astronomy.
- Technical Approach: Enable training of unrolled networks on full-scale data using multi-node and multi-GPU computing, using distributed physics, denoiser, prior and backward gradients with a simple API in the DeepInv library.
- Key Achievement: Successfully integrated with a simple API in the widely used open-source DeepInv library, and demonstrated on large-scale 3D tomography problems (500^3 voxels), previously infeasible for most methods. Benchmarked within the BenchOpt framework on Jean Day using 16 H100 GPUs (10s per sample).
- Impact of Full-Scale Learning: Removes a major limitation and opens a new area of research at realistic scales.
- Accessibility: Makes large-scale AI-based inverse problem learning accessible to a broader community beyond HPC experts.
- Future Applications: Can be extended to other models and large-scale applications, particularly in large-scale electro tomography and radio-interferometry.
Top: Training curves showing convergence behaviour of the proposed distributed unrolled method. Bottom: Qualitative comparison of reconstructions, including ground truth (GT), sparse baseline, untrained network output, and the trained unrolled network (3 iterations). Our large-scale framework enables efficient training of this unrolled architecture across 16 H100 GPUs, making it feasible to handle high-resolution tomography data (500^3 voxels).
At a glance
Project Metrics
Data as of 1 July 2026, unless stated otherwise.
Save the Date
Exa-DI events
Discover the next Exa-DI events: our seminars and conferences, as well as partner events
august, 2026
The Team
The Exa-DI Team
Discover the members
Félix Kpadonou
CEA research engineer
Institute for Research on the fundamental laws of the universe (CEA Irfu)

Sergio Pastor Perez
Inria research engineer
Inria Bordeaux
Iole Bolognesi
CNRS research engineer
MdlS
Vivien Krauss
CNRS research engineer
Inria Bordeaux
Romain Margheriti
CEA research engineer
Institute for Research on the fundamental laws of the universe (CEA Irfu)
Working Group leaders
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