Hi, I'm

Grégoire
Marousé

Back-end Java developer · Finishing my Computer Science degree · Applying to DTU

Back-end Java developer at Crédit Agricole Technologies & Services since September 2025, on payment enrolment APIs. I'm finishing my Computer Science degree and applying to the Industry MSc in Computer Science and Engineering at the Technical University of Denmark (DTU). I'm looking for a company around Copenhagen to host the project.

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Grégoire Marousé

About

About me

I build back-end services in Java. I have been doing it since September 2025 at Crédit Agricole Technologies & Services in Vannes, France, the IT arm of France's largest mutual banking group. My squad builds the enrolment APIs for digital payment methods. I extend and maintain them, with the security and compliance constraints that come with a banking system.

I'm finishing a three-year Computer Science degree, ranked 1st of 80 in my last full semester. Next, I'm applying to the Industry MSc in Computer Science and Engineering at the Technical University of Denmark (DTU), and to ENSIBS in France in parallel. I want to keep learning this way: by building software inside a company.

The topics I care about: AI applied to software engineering and cybersecurity. Developer tooling, anomaly detection, application security, DevSecOps. I'm looking for a company in the Copenhagen area, Lyngby included, to host my Industry MSc project on those topics. The programme runs for four years, from September 2027, so the collaboration is a long one. Large organisations interest me most: I want my work to feed into something bigger than the projects I build on my own. As a French citizen, I can work in Denmark without a permit.

Four years from September 2027EU citizen, no work permit neededOpen to relocating to CopenhagenApplying to DTU · Industry MSc
LinkedIngregoiremarouse@gmail.com

Skills

What I work with

Java back-end

REST APIs inside a banking information system, in an agile team.

JavaJava
Spring BootSpring Boot
MavenMaven
PostmanPostman

Applied AI

Training and benchmarking machine learning and deep learning models, automations built around models, and AI assistants.

scikit-learnscikit-learn
KerasKeras
n8nn8n
ClaudeClaude
GitHub CopilotGitHub Copilot

Security

CVE remediation, security gates in continuous integration, and penetration testing in a lab environment.

SonarQubeSonarQube
JFrog XrayJFrog Xray
NmapNmap
MetasploitMetasploit

Cryptography

The mathematics behind security: modular arithmetic, primality testing, key exchange protocols.

RSARSA
Diffie-HellmanDiffie-Hellman
AESAES
SHA-256SHA-256
OpenSSLOpenSSL

Delivery & CI/CD

From ticket to release: GitLab pipelines, artifacts published to JFrog, GitOps delivery on Kubernetes, across four successive environments.

JiraJira
GitLab CI/CDGitLab CI/CD
Argo CDArgo CD
KubernetesKubernetes
DockerDocker
JFrog ArtifactoryJFrog Artifactory
GitGit
BashBash

Data

Data modelling and access, querying and bulk processing, GDPR-compliant purging.

PostgreSQLPostgreSQL
MySQLMySQL
MongoDBMongoDB
SQLiteSQLite
Deno KVDeno KV

Web & scripting

Full-stack web applications, from prototype to VPS deployment. Algorithmics and scripting.

PythonPython
TypeScriptTypeScript
JavaScriptJavaScript
ReactReact
Deno FreshDeno Fresh
TailwindCSSTailwindCSS
WordPressWordPress

Systems & self-hosting

Virtual machines for test environments and labs. I have self-hosted my projects on a VPS since 2021: Linux, Docker, reverse proxy, TLS certificates and DNS.

LinuxLinux
OVHOVH
TraefikTraefik
Let's EncryptLet's Encrypt
VirtualBoxVirtualBox
WindowsWindows
macOSmacOS

Projects

A selection of what I've built

AI platforms and tools

AI platforms and tools

In progress

Development of platforms and tools built around AI models to carry out well-defined tasks, making digital services affordable for individuals and small organisations.

EntrepreneurshipApplied AIAutomation
Kioptrix Level 2

Kioptrix Level 2

Completed

Penetration test on a deliberately vulnerable machine, done as a lab: Nmap reconnaissance, SQL injection, remote command execution for a reverse shell, then a kernel exploit to root.

CybersecurityPentestSQL injectionPrivilege escalation
Reboot Éco

Reboot Éco

In progress

Company selected by the UBS Foundation's Agitateur programme (season 4). Collecting, repairing and recycling IT hardware for a more sustainable digital sector.

EntrepreneurshipHardwareProject management
Def'IUT

Def'IUT

Live

Coding-challenge platform for my university department: authentication, submission handling and isolated code execution in a Docker sandbox. Full-stack architecture with a REST API.

DockerExpressJSReactMySQL
Pokémon TCG collection manager

Pokémon TCG collection manager

Live

Personal tool for managing a Pokémon card collection: photo-based import, automated scraping of market prices and tracking of the collection's estimated value.

ScrapingPostgreSQLAutomationValue tracking
SFX website

SFX website

On hold

Blog with a custom back-office: article management, authentication and deployment, built to showcase my high school's educational programme. Deno KV as the database, no SQL server.

Deno FreshTypeScriptDeno KV
AI vs Maths

AI vs Maths

Completed

International Baccalaureate extended essay in computer science, graded B. Training and benchmarking machine learning and deep learning models (scikit-learn, Keras) to solve degree-2 and degree-5 polynomials.

PythonMachine LearningNeural networksMathematics
Primality testing

Primality testing

Completed

International Baccalaureate mathematics exploration: a study of primality tests, including Solovay-Strassen, with proofs of the Legendre symbol and its generalisation, the Jacobi symbol.

MathematicsCryptographyModular arithmeticIB essay
Unity mini-game

Unity mini-game

Completed

Game built with Unity's 3D Game Kit as part of a tutoring project for high school students, used to teach the basics of C# development.

C#UnityTeaching