Software developer · Applied AI
Grégoire Marousé
I build banking APIs in Java at Crédit Agricole, as an apprentice alongside my degree. I want to work in software engineering and apply AI to demanding fields: cybersecurity, finance, science.
- ApprenticeshipCrédit AgricoleBack-end Java developer since 2025
- Studies1st out of 80in semester 3 of the BUT Informatique (Bachelor of Technology in Computer Science)
- Next stepSeptember 2027Master’s or engineering degree, in France or abroad
My skills
Build
REST APIs and a Spring Batch job for a bank at Crédit Agricole, unit tests included, and full-stack web applications in projects.
Java
Spring Boot
Maven
TypeScript
React
Deno Fresh
PostgreSQL
MySQL
Seen inCrédit Agricole →Def’IUT →Noti Assistant →Web Services →
Ship
From ticket to production at Crédit Agricole, and my own server since 2021.
GitLab CI/CD
Docker
Kubernetes
Argo CD
JFrog Artifactory
Linux
Traefik
Secure
Platform upgrades and CVE fixes at Crédit Agricole, security checks in CI, and black-box penetration tests in class.
SonarQube
JFrog Xray- Nmap
Metasploit
AI
Models trained and compared in high school, an app that transcribes and writes, Copilot at Crédit Agricole, and Claude every day on my projects, with my own tools and reusable instructions.
Python
scikit-learn
Keras
n8n
Claude
GitHub Copilot
Ways of working
In an agile team at Crédit Agricole, with code review. Project lead on Def’IUT and team lead on all my other degree projects.
- Scrum
- Kanban
Jira
Git
Seen inCrédit Agricole →Def’IUT →
Model
The maths and science behind the code: number theory for primality tests, physics measurements with their uncertainties, the speed of a chemical reaction, and the training data for my AI models.
Languages
- FrançaisNative
- EnglishEnglish · B2
- EspañolSpanish · B1
- 日本語Japanese · beginner
Levels on the European scale (CEFR), from A1 to C2.
Beyond code
Go and puzzles
Thinking for a long time before playing a stone, and being ready to go back on my ideas: analysing and solving problems. Ranked up to 1 kyu online, depending on the period and the platform.
Japanese culture
Curious and open-minded, I am learning Japanese to discover what is beyond the language: school, daily life, how people relate to each other.
Cooking
Rigour, organisation and creativity, in cooking as in code.
Watch the video
Astrophysics
An interest since childhood, out of curiosity and a taste for the unknown and for discovery. I took it as my physics option at IB Higher Level: stars, how they evolve, cosmology.
Let’s talk about what’s next.
A question about my path, or an offer? Write to me.
gregoiremarouse@gmail.comSéné, near Vannes, Brittany · ready to relocate, in France or abroad
My path
Seven steps, played as a game of go
Each step is one of my moves, the white stones, in a real game of go.
How to read my path
- 1Middle schoolFirst video games↓
- 22021My first server↓
- 32022 – 2024Two baccalaureates↓
- 42024 – 2027BUT Informatique↓
- 5March 2025Winner of L’Agitateur↓
- 62025 – 2027Apprenticeship at Crédit AgricoleNow↓
- 7September 2027The next move↓
Skip to my skills ↓1Middle school
My first video games, in Unity and C#
Unity and C#, self-taught on YouTube
Six tutorial series from the TUTO UNITY FR channel
In middle school, I taught myself to make video games with these six tutorial series, from the basics of C# to a multiplayer game. Each link opens the series on YouTube.
22021
My first professional website, on my own server
An OVH server with Ubuntu that I still manage today: Docker, Traefik, domain names and certificates. Since then, it has hosted the websites I build.
Website for Sandrine Marousé, sophrologist
In React, 2021
The website for my mother’s business in Séné (sophrology is a relaxation method). I rebuilt it later, much better, and it is still online.
32022 – 2024
French baccalaureate and International Baccalaureate, at the same time
Two diplomas at once, about 45 hours of classes a week: the French general baccalaureate and the International Baccalaureate.
The Extended Essay
AI and polynomial equations
Extended Essay in computer science, grade B
Written when ChatGPT came out. On 100,000 polynomials of degree 2 and 5, I compared decision trees, random forests and neural networks (scikit-learn, Keras). Their error rate stays between 16 and 22%: they are assistants, not solvers.
Internal assessments4 projects: click one to open it
CAS: creativity, activity, service5 projects: click one to open it
Tutoring
An introduction to Unity for high-school students
Tutoring, as part of the IB
I introduced a few younger students to Unity: we started from the 3D Game Kit to build a mini-game, and I taught them the basics of C# on the way.
42024 – 2027
BUT Informatique (Bachelor of Technology in Computer Science), Vannes
A three-year degree at the IUT de Vannes (Université Bretagne Sud’s institute of technology), track: deployment of secure, connected applications, as an apprenticeship. Ranked 2nd out of 102 in semester 2, then 1st out of 80 in semester 3.
Selected projects
Noti Assistant
Course project, year 2, then a personal project
From an audio recording to a document written by AI, in three versions: n8n, FlutterFlow, then a web app. You can listen again to each uncertain word before the AI writes, and the transcription stays in the EU. The use case is fictional; I am now focusing it on local news.
Def’IUT
Team project, year 2 · project lead
A coding challenge platform: players’ code runs in isolated Docker containers to protect the server. I led the project in a team of four students (React, Express, MySQL, GitLab CI).
5March 2025
Winner of L’Agitateur with Reboot Éco
L’Agitateur is the Université Bretagne Sud Foundation’s call for projects, to support student initiatives such as starting a business. I presented Reboot Éco to a jury and won €1,500 for the project.
Reboot Éco
Project started in 2024, registered business since 2025
I collect and repair computer equipment on my own, to sell it at a low price: against the digital divide and electronic waste. More than 40 computers and many accessories collected, and €500 of repair income in the first six months, alongside my studies.
62025 – 2027Now
Apprentice developer at Crédit Agricole
Since September 2025, I have been a back-end Java developer at Crédit Agricole Technologies & Services in Vannes, the IT partner of Crédit Agricole’s 39 regional banks. My team builds and runs the APIs that add bank cards to mobile payment apps (Apple Pay, Samsung Pay, Crédit Agricole Paiement Mobile). This is banking data, covered by GDPR and the PCI DSS standard.
What I do there
From ticket to productionSee the stepsHide
7September 2027Next
The next move
From September 2027, I am aiming for a master’s or an engineering degree, in France or abroad, to go further in software engineering and applied AI. I am looking for the school and, if my studies include work, the company: a large company in a critical sector, such as banking or finance, where security and compliance are not negotiable. I find that in a demanding place, you learn more, and the work also has more meaning.