Biography

I am Sacha, PhD Student at Imperial College under the supervision of Philippa Gardner and a member of the Verified Trustworthy Software Specification Group . I am working on Gillian, a parametric symbolic execution tool for symbolic testing, verification and automatic compositional testing. My full CV is available..

In my free time, I try to contribute to some open-source projects I love. I am an OCaml enthusiast, amateur magician and I like to rollerblade my way through London.

Publications

José Fragoso Santos
Petar Maksimović
Sacha-Élie Ayoun
Philippa Gardner
PLDI 2020
Petar Maksimović
Sacha-Élie Ayoun
José Fragoso Santos
Philippa Gardner
CAV 2021

Committees and Panels

Programming language Mentoring Workshop @ Principles of Programming Languages (POPL) 2021
Sept - Oct 2021
22nd International Conference on Verification, Model Checking, and Abstract Interpretation
Jan 2021
Student Volunteer Chair and Local organiser
51st ACM SIGPLAN Symposium on Principles of Programming Languages
Jan 2024
I am particularly proud to have been a part of the organising committee for POPL 2024, which was held in London. As student volunteer chair, I had the privilege to meet and work with 50 students from all over the world, running up and down to make sure the experience was as smooth as possible for conference attendees. In addition, as local organsier, I helped with several logistical aspects of the conference, including communication with the venue, designers, conference manager etc.

Teaching

Taught by Philippa Gardner
Masters level
  • Tutorial Helper
  • Coursework writing
  • Coursework marking
  • Exam question design
Autumn 2019 | Autumn 2020 | Autumn 2021 | Autumn 2022 | Autumn 2023
Teaching Assistant
Taught by Paul Kelly
Masters level
  • Coursework marking
Spring 2019
Teaching Assistant
Taught by Azalea Raad and Herbert Wickliky
Undergraduate level
  • Tutorial Helper
  • Coursework marking
Autumn 2020 | Autumn 2021 | Autumn 2022 | Autumn 2023
Teaching Assistant
Taught by Oana Cocarscu
Masters level
  • Tutorial Helper
  • Coursework marking
Autumn 2019
Teaching Assistant
Taught by Thomas Clarke
Undergraduate level
  • Tutorial Helper
  • Coursework marking
  • Group project supervision
  • Project marking
Spring 2021
Teaching Assistant
Taught by Manon Flageat, Luca Grillotti, Viet Pham Ngoc and Pancham Shukla
level
  • Tutorial Helper
  • Group tutoring
Spring 2022

Supervision

Continuous Reasoning for Real-World Program Analysis Tools
Co-supervisor
Master's thesis - Alexis Marinoiu
2020

This project extends Gillian with continuous reasoning foundations that substantially advance its applicability to real-world projects. In particular, Alexis has: extended its instantiations for C and JavaScript in order to allow them to analyse multi-file projects; and incorporated a mechanism for re-using previously-stored results in order to focus analysis on only the fragments of the source program that have changed. Finally, by analysing two real-world C and JavaScript projects, Alexis has demonstrated the significant improvement in the usability of Gillian by a general developer, as well as the correctness of our implementation.

This project was awarded the Distinguished status.

Principled Debugging for Real-World Program Analysis Tools
Co-supervisor
Master's thesis - Radu Lacraru
2020

This projects lays out the foundations for a reporting system for Gillian that systematically organises the reports produced by Gillian into a hierarchical structure over which the Gillian developer has full control; reporters that can export that hierarchical structure into useful formats, such as textual log files and database reports and a language-specific reporting mechanism that the Gillian developer can easily instantiate for their target language of choice

Gillian: Principled Debugging for Real-World Program Analysis Tools
Co-supervisor
Master's thesis - Matthew Ho
2021

This project presents an interactive debugger for Gillian, building on the infrastructured built by Radu Lacraru in his project. It is incorporated into the Visual Studio Code editor and substantially improves the experience of developing and using the tool. Therefore, this project constitutes the first, essential step towards bringing the platform closer to students and general programmers. As part of the project, Matthew improved and structured the existing general mechanism for creating and storing queryable log traces during Gillian's symbolic execution, and used this mechanism to power the debugger as well as to provide an interface for parametric lifting of error messages from Gillian's intermediate representation to the level of the target language.

This project received a Distinction grade.

Gillian: Principled Debugging for Compositional Symbolic Execution
Co-supervisor
Master's thesis - Nat Karmios
2022

Based on Matthew Ho’s and Radu Lacraru’s work, Nat pushed Gillian’s debugging experience to an entirely new league. He used the queryable log traces to their full potential, and designed a new interface, integrated in VSCode, to debug symbolic execution assertion unification. This interface is a strong step towards the improvement of the interactivity of Gillian.

This project was awarded the Distinguished status, and Nat joined our group as a research engineer to help improving Gillian.

Contact me

  • Address

    Department of Computing
    Imperial College London
    South Kensington Campus
    London SW7 2AZ, United Kingdom