Freelancer profile translated to English.
Back to original languageAbout Guillaume
Tech Lead / Senior Fullstack Engineer – TypeScript, Node.js, React/Angular, AWS
Full stack developer for over 12 years, I support teams throughout the entire application lifecycle: business scoping, technical design, development, deployment, and industrialization. I work with a constant focus on clarity, quality, and maintainability.
Full Stack Technical Expertise
- **Frontend**: React.js, Next.js, Angular, Ionic
- **Backend**: Node.js, TypeScript, microservices, REST APIs
- **Databases**: PostgreSQL, MongoDB
- **Cloud & DevOps**: AWS (EC2, S3, Lambda, Batch), Docker, Kubernetes, CI/CD (GitHub Actions, Jenkins, GitLab CI), IaC (Pulumi)
- **Software Quality**: unit and integration tests, >80% coverage, code reviews, documentation, clean code
Strengths
- Rapid Adaptationto technical environments and project contexts
- Clear Dialogue with Business Stakeholdersto transform needs into concrete solutions
- **Architecture and Delivery**: pragmatic design, secure deployment pipelines, and monitoring
- **Autonomy and Collaboration**: 100% remote, developer mentoring, sharing standards and best practices
Recent Achievements
- **SNCF (2021–2024)**: Design and deployment of two cloud-native HR platforms for managing over 100,000 employees. National V1 in less than 6 months, unanimous adoption, additional funding unlocked, ~90% reduction in processing time.
- **Quality & Industrialization**: Implementation of CI/CD pipelines with ~1000 integrated tests, multi-environment deployments (Docker, Kubernetes, Jenkins).
What I'm Looking For
Long-term assignmentswhere technical requirements are highand where I can add value while growing in a stimulating environment.
// developer fullstack developer full stack backend frontend react node.js full stack developer
English
Fluent
Spanish
Conversational
Portuguese
Native or bilingual
French
Native or bilingual
Remote only
Primarily works remotely
Experience
- SNCF DGEX SolutionsLead Fullstack Developer Angular / Node.jsTRANSPORTATIONMay 2021 - December 2023 (2 years and 7 months)As a Lead Fullstack Developer, I led the technical side and participated in the development of two major HR digitalization projects at SNCF: a scheduling management tool and an integrated HR planning system, both on a national scale.I oversaw the technical aspects from design to implementation, taking charge of architectural choices, development, and deployments.Using technologies like Angular, Node.JS, MongoDB, PostgreSQL, and OPS tools (Jenkins, Helm, Kubernetes), I led these projects with deep commitment, addressing technical and operational challenges.Results: Transition from paper and pencil to a complete digital solution, including an automatic schedule and shift optimization engine. 2.5-year mission in full remote with a technical reference role. Radical transformation of the business, significant reduction in planning time, and reliable production across the country.
- AI Video ServiceFullstack / Ops DeveloperFILM AND AVAugust 2024 - November 2024 (2 months)Paris, France[WIP]Design, development, and deployment of an online application for video processing, transcription, and automated subtitle embedding.Application (fullstack): NextJs, TypescriptDatabase: MongoVideo Processing: Python, Ffmpeg, Whisper (voice transcription)Architecture / Deployment: AWS (EC2, Batch, S3), Pulumi
- Les MitronsFullstack Developer Architect Ionic / Angular / Node.jsRESTAURANTS AND FOOD SERVICEFebruary 2021 - March 2021 (2 months)Update to V2 (backend and frontend) of the Les Mitrons application available on Android and iOS (Ionic / Angular Application).Integration of new views from the mockups.Implementation of new features including:- Deep link management- Recipe sharing, via automatic screenshot or deep link (SMS / email, etc.)- Translation support: development of a translation system for database entities, and use of i18n in the app for in-app wording- Added support for photos associated with recipes (with Amazon S3)- UI / UX Improvement (API and request optimization, addition of a filtering system on different entities, etc.)Database updatePublication and deployment of mobile applications and the server
Reviews
Colette
SNCF DGEX Solutions - Paris - AST&Digital
Reviewed on 1/10/2024
Guillaume has just completed a 2.5-year mission with us. He served as the lead fullstack developer within a small team of 2 to 3 developers and delivered very high-quality work. Guillaume worked 100% remotely, and it worked very well. He proved to be flexible, patient, educational, and proactive. Working with him was a very positive experience, and I recommend him without hesitation.
Colette
SNCF DGEX Solutions
Reviewed on 7/23/2021
These first two months of the mission with Guillaume went very well. Guillaume is comfortable in web application development and is proactive. He is attentive, organized, and rigorous; I highly recommend him.
Recommendations
CB
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Education
- Software Architect Master's DegreeInsta Paris2015
- Computer Science Bachelor's DegreeUniversité Diderot (Paris VII)2013
Certifications
- Artificial Intelligence (Introduction: Machine Learning, Neural Networks, Deep Learning)IPCA (Instituto Politécnico do Cávado e do Ave)2024
- Introduction to Corporate Social Responsibility (CSR) for DevelopersSNCF2023