Personal Information
Name
Lylian SIFFRE
Email
lylian@siff.re
Github
https://github.com/xonturis
LinkedIn
https://www.linkedin.com/in/lylian-siffre
ORCID
https://orcid.org/0009-0004-5743-9337
Education
PhD in Computer Science (ongoing)
IMT Atlantique (Nov. 2024 - Nov. 2027)
Supervision: Thomas Ledoux, Renaud Pawlak, John Guery
Summary: Since the topic evolves during the thesis, for now, refer to publications/preprints/posters.
Engineer’s Degree in Computer Science
Polytech Nantes, Université de Nantes (Sept. 2021 - Sept. 2024)
Topics: Advanced database management, data quality, data analysis, AI algorithms.
Associate Degree in Computer Science
IUT de Nantes, Université de Nantes (Sept. 2019 - June 2021)
Topics: Web development (HTML/CSS/JS & PHP), technical solution design (UML), project management, databases, Java, Python, C, statistics, linear algebra.
High School Diploma – STI2D (SIN specialization)
Lycée Gustave Eiffel de Bordeaux (June 2019)
With Highest Honors (Mention Très Bien).
Professional Experience
PhD Student
Kapela, Nantes (Nov. 2024 - Nov. 2027)
- Study of Local-First Software’s impact on green software design
- Scientific outreach to industry professionals
- Research valorization with industrial partners
Research Engineer (Apprenticeship)
Impakt, Nantes (Sept. 2021 – Sept. 2024)
- Authored and published a research paper at a European conference (see Publications).
- Developed energy measurement software (see Publications).
- Designed and compared efficiency between eco-designed and non-eco-designed prototypes.
Backend Developer Intern
ValueChecker, Stockholm, Sweden (June 2023 - Aug. 2023)
- REST standardization of an HTTP API.
- Identified and corrected non-compliant issues.
- Communicated changes to the team.
- Wrote documentation to maintain REST compliance.
- SQL query optimization.
- API testing and CI/CD integration.
- Participated in recruitment processes.
Software Engineer Intern
LS2N, Nantes (Apr. 2021 – June 2021)
- Data warehouse management.
- SQL database extraction.
- Data quality reporting.
- Team workflow methodology implementation.
Technical Skills
- Data Analysis: Numpy, Pandas, Matplotlib, scikit-learn, Tableau, Excel
- Design: UML, Entity-Relationship
- Programming: Python, Java, Go, JavaScript, PHP, C, C++
- Web Frameworks: React, Vue
- Languages: Native French, English (TOEIC 965/990, 2022)
- Documentation: LaTeX, Word
Research
My research interests are:
- Energy consumption of Local-First Software
- Building a methodology for shifting SaaS towards Local-First Software
Feel free to contact me if you think we could collaborate!
Publications
Lylian Siffre, Thomas Ledoux, Renaud Pawlak, John Guery. Local Computing vs. Cloud Computing: An Empirical Study of Energy Consumption. IEEE/ACM 18th International Conference on Utility and Cloud Computing, Dec 2025, Nantes, France. pp.1-10. ⟨hal-05324506⟩
Lylian Siffre, Thomas Ledoux, Renaud Pawlak, John Guery. Local-First Software for Green IT. ICT4S 2025 - International Conference on Information and Communications Technology for Sustainability, Jun 2025, Dublin, Ireland. pp.1-10. ⟨hal-05037019⟩
Lylian Siffre, Gabriel Breuil, Adel Noureddine, Renaud Pawlak. Demeter: An Architecture for Long-Term Monitoring of Software Power Consumption. 17th European Conference on Software Architecture, Sep 2023, Istanbul, Turkey. ⟨hal-04231337⟩
Keynotes
“Local-First Software : L’informatique frugale, résiliente et centrée sur l’humain au-delà du tout-Cloud” (in French) @ Verdinum : L’IA frugale dans ses différentes dimensions, November 6th 2025. More details…
Posters
Lylian Siffre. 2025. Local-First Software for Green IT. Greendays 2025, Rennes. https://siff.re/public/Position_Paper_Poster.pdf
Reviews
- Reviewer for UCC'25 Poster Session
- Sub Reviewer for IEEE CLOUD 2025
Teaching
- Introduction to programming, Programming project, IMT Atlantique (1st-year Engineering students, 2025)
- Introduction to Research, IMT Atlantique (3rd-year Engineering students, 2025). With Hélène Coullon
- Object-Oriented Programming, Databases & Networks Project, IMT Atlantique (1st-year Engineering students, 2025)
- Object-Oriented Programming, IMT Atlantique (1st-year Engineering students, 2025)
Mentorship
- Supervised a group of three 3rd-year engineering students at IMT Atlantique for a Frontend/Backend project. (October - ongoing)
Output: ongoing - Supervised a 2nd-year engineering intern at Stack, LS2N (Jan–Feb 2025).
Output: https://gitlab.inria.fr/lsiffre/service-energy-monitor
Organization
- Volunteer Student at UCC'2025
- Stack Team Seminar 2025:
- Program
- Session Chair
Other Activities
Board Member
Communication committee member for a French nonprofit (1901 law) (2024 – ongoing).
Vice President & Treasurer
Financial management for a nonprofit (2020 – 2021).
Minecraft Game Server Project Lead
(Agile team management, developer recruitment, inter-team coordination, Java development, database/server administration) (2018 - 2021).
IUT Projects:
Personal Information
Name
Lylian SIFFRE
Email
lylian@siff.re
Github
https://github.com/xonturis
LinkedIn
https://www.linkedin.com/in/lylian-siffre
ORCID
https://orcid.org/0009-0004-5743-9337
Education
PhD in Computer Science (ongoing)
IMT Atlantique (Nov. 2024 - Nov. 2027)
Supervision: Thomas Ledoux, Renaud Pawlak, John Guery
Summary: Since the topic evolves during the thesis, for now, refer to publications/preprints/posters.
Engineer’s Degree in Computer Science
Polytech Nantes, Université de Nantes (Sept. 2021 - Sept. 2024)
Topics: Advanced database management, data quality, data analysis, AI algorithms.
Associate Degree in Computer Science
IUT de Nantes, Université de Nantes (Sept. 2019 - June 2021)
Topics: Web development (HTML/CSS/JS & PHP), technical solution design (UML), project management, databases, Java, Python, C, statistics, linear algebra.
High School Diploma – STI2D (SIN specialization)
Lycée Gustave Eiffel de Bordeaux (June 2019)
With Highest Honors (Mention Très Bien).
Professional Experience
PhD Student
Kapela, Nantes (Nov. 2024 - Nov. 2027)
- Study of Local-First Software’s impact on green software design
- Scientific outreach to industry professionals
- Research valorization with industrial partners
Research Engineer (Apprenticeship)
Impakt, Nantes (Sept. 2021 – Sept. 2024)
- Authored and published a research paper at a European conference (see Publications).
- Developed energy measurement software (see Publications).
- Designed and compared efficiency between eco-designed and non-eco-designed prototypes.
Backend Developer Intern
ValueChecker, Stockholm, Sweden (June 2023 - Aug. 2023)
- REST standardization of an HTTP API.
- Identified and corrected non-compliant issues.
- Communicated changes to the team.
- Wrote documentation to maintain REST compliance.
- SQL query optimization.
- API testing and CI/CD integration.
- Participated in recruitment processes.
Software Engineer Intern
LS2N, Nantes (Apr. 2021 – June 2021)
- Data warehouse management.
- SQL database extraction.
- Data quality reporting.
- Team workflow methodology implementation.
Technical Skills
- Data Analysis: Numpy, Pandas, Matplotlib, scikit-learn, Tableau, Excel
- Design: UML, Entity-Relationship
- Programming: Python, Java, Go, JavaScript, PHP, C, C++
- Web Frameworks: React, Vue
- Languages: Native French, English (TOEIC 965/990, 2022)
- Documentation: LaTeX, Word
Research
My research interests are:
- Energy consumption of Local-First Software
- Building a methodology for shifting SaaS towards Local-First Software
Feel free to contact me if you think we could collaborate!
Publications
Lylian Siffre, Thomas Ledoux, Renaud Pawlak, John Guery. Local Computing vs. Cloud Computing: An Empirical Study of Energy Consumption. IEEE/ACM 18th International Conference on Utility and Cloud Computing, Dec 2025, Nantes, France. pp.1-10. ⟨hal-05324506⟩
Lylian Siffre, Thomas Ledoux, Renaud Pawlak, John Guery. Local-First Software for Green IT. ICT4S 2025 - International Conference on Information and Communications Technology for Sustainability, Jun 2025, Dublin, Ireland. pp.1-10. ⟨hal-05037019⟩
Lylian Siffre, Gabriel Breuil, Adel Noureddine, Renaud Pawlak. Demeter: An Architecture for Long-Term Monitoring of Software Power Consumption. 17th European Conference on Software Architecture, Sep 2023, Istanbul, Turkey. ⟨hal-04231337⟩
Keynotes
“Local-First Software : L’informatique frugale, résiliente et centrée sur l’humain au-delà du tout-Cloud” (in French) @ Verdinum : L’IA frugale dans ses différentes dimensions, November 6th 2025. More details…
Posters
Lylian Siffre. 2025. Local-First Software for Green IT. Greendays 2025, Rennes. https://siff.re/public/Position_Paper_Poster.pdf
Reviews
- Reviewer for UCC'25 Poster Session
- Sub Reviewer for IEEE CLOUD 2025
Teaching
- Introduction to programming, Programming project, IMT Atlantique (1st-year Engineering students, 2025)
- Introduction to Research, IMT Atlantique (3rd-year Engineering students, 2025). With Hélène Coullon
- Object-Oriented Programming, Databases & Networks Project, IMT Atlantique (1st-year Engineering students, 2025)
- Object-Oriented Programming, IMT Atlantique (1st-year Engineering students, 2025)
Mentorship
- Supervised a group of three 3rd-year engineering students at IMT Atlantique for a Frontend/Backend project. (October - ongoing)
Output: ongoing - Supervised a 2nd-year engineering intern at Stack, LS2N (Jan–Feb 2025).
Output: https://gitlab.inria.fr/lsiffre/service-energy-monitor
Organization
- Volunteer Student at UCC'2025
- Stack Team Seminar 2025:
- Program
- Session Chair
Other Activities
Board Member
Communication committee member for a French nonprofit (1901 law) (2024 – ongoing).
Vice President & Treasurer
Financial management for a nonprofit (2020 – 2021).
Minecraft Game Server Project Lead
(Agile team management, developer recruitment, inter-team coordination, Java development, database/server administration) (2018 - 2021).
IUT Projects: