Theo Lejeune
Cybersecurity Engineer & Web Developer
ABOUT
Passionate cybersecurity engineer and web developer specializing in security audits and full-stack development. Expertise in designing robust and secure solutions with modern technologies including Azure and AWS cloud platforms. Capable of managing complete projects from design to deployment with a strong focus on security best practices.
EXPERIENCES
Cybersecurity Engineer / Pentester
Thales
2024 - Present
- Conducting security audits on critical web applications and embedded systems
- Azure and AWS cloud platform security assessments
- Writing detailed audit reports with security recommendations
- Cybersecurity guidance and support for development teams
- Security technology research and threat intelligence
Web3 Cybersecurity Engineer
Intern / OpCodes
2022
- Smart contract audits for blockchain projects
- Smart Contract development on Solana in Rust
- Writing audit reports with security recommendations
Full-Stack Developer
Freelance / Diagmarket.fr
2024 - Present
- Development of a comprehensive energy audit search platform
- Backend architecture in Golang with REST API
- Modern frontend with SvelteKit
- MongoDB database management
Package Manager & Systems Developer
Thales
2022 - 2024
- Management of C++ and JEE components for a critical mapping and communication system
- Development of new features
- Code maintenance and optimization
- Technical and functional documentation
IoT Developer & System Administrator
Intern / IVS
2021
- Development of two applications for smart device management
- Installation application with automatic detection
- Real-time monitoring system with WebSocket
- System administration activities
EDUCATION
Computer Science Engineer - Cybersecurity Specialization
IMT Nord Europe (formerly Telecom Lille)
2017-2022
My computer science degree with a cybersecurity specialization at IMT Nord Europe provided me with solid expertise in computer systems, networks, digital security, software development, and project management. I learned to design, audit, and protect infrastructures against current threats while developing technical rigor and a strong sense of responsibility.