The days are free of charge (cocktail, lunch and breaks included), but you’ll have to finance the missions yourself. We have to limit the number of registrations for the days for financial reasons. Here’s the registration link:

These days are organized within the GDR GPL and the GT YODA (which I co-chair with Simon Bliudze and Rabéa Ameur-Boulifa). The IMT and the ANR SeMaFoR project (Thomas Ledoux) also help me finance these days.

The VELVET days will be held at IMT Atlantique, 4 rue Alfred Kastler, 44307 Nantes

Invited speaker

Daniel Sokolowski (St. Gallen Switzerland)

Daniel Sokolowski is interested in distributed systems and cloud technology from a Programming Languages and Software Engineering perspective. Currently, he is mainly focussing on advancing Infrastructure as Code (IaC), aiming at robust deployments in modern DevOps organizations.


Reliable Infrastructure as Code for Decentralized Organizations


In DevOps, organizational structures foster cross-functional teams that independently develop and operate applications. Yet, these applications often rely on each other, necessitating coordination between teams. Further, DevOps extends to the technical domain, where DevOps promotes automation throughout the software lifecycle. Infrastructure as Code (IaC) is key to this automation, applying software development practices to operational tasks like software deployment and configuration. Ensuring the reliability of both inter-team coordination and IaC programs is critical. Failures in coordination or errors in IaC can lead to system malfunctions or expose them to significant security vulnerabilities.

In this talk, I explore three aspects of achieving reliable IaC within decentralized organizations. Firstly, I address the challenge of automating deployment coordination in a decentralized environment. Existing approaches are typically manual or centralized. To overcome this issue, I present µs, automating coordination of IaC programs in a decentralized fashion. Secondly, I delve into the intricacies of safely updating components in distributed systems, emphasizing the need for coordinated timing to ensure distributed transactions are successful. I will discuss methods for implementing safe dynamic software updating (safe DSU) in a decentralized context and its integration into IaC. Thirdly, the correctness of IaC programs is crucial. I present Automated Configuration Testing (ACT), enabling efficient unit testing of IaC programs, its implementation ProTI, and how it is the stepping stone to verifying IaC programs.


The current program is as follows (It may evolve a bit):

13th of December (IMT Atlantique, J142)

  • 13h45-14h Introduction
  • 14h-14h30 Eloi Perdereau and Jacques Noyé - Overview and formalization of configuration languages
  • 14h30-15h Simon Bliudze - Towards High-Level Models for Safe Coordination in the Cloud
  • 15h-15h30 Matthieu Acher - Configuration and Software variability
  • 15h30-16h Break
  • 16h-17h Tutorial by Sophie Cerf and Eric Rutten - Control theory
  • 17h-18h Tutorial by Frédéric Loulergue - The deductive program verification tool Why3
  • 19h Cocktail in Nantes

14th of December (IMT Atlantique, J142)

  • 8h30 Welcome coffee
  • 9h-10h15 Invited speaker Daniel Sokolowski (St. Gallen Switzerland)
  • 10h15-10h45 Jolan Philippe and Hélène Coullon - Fast Choreography of Cross-DevOps Reconfiguration with Ballet
  • 10h45-11h Break
  • 11h-11h30 Gwen Salaun - Automated Verification of TOSCA Workflows
  • 11h30-12h Olivier Barais - Adaptative authentication
  • 12h-12h30 Sophie Cerf - Towards control of task-level and cluster-level in the PULSE project
  • 12h30-13h Daniel Balouek - Challenges and Opportunities of Urgent Applications across the Continuum
  • 13h Lunch


As for the hotel, we’d advise you to stay in a hotel in the center of Nantes, which will be more convenient in any case and will be nicer for you.