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Sebastien Mathieu
Verified Expert in Engineering
Full-stack Developer
Christchurch, Canterbury, New Zealand
Toptal member since September 25, 2020
Bio
Sebastien comes from a background of research in robotics and machine learning. His preference is working in the web domain as it can scale quickly, and he's also passionate about data science. He works best when working through a problem and feels challenged. Sebastien is a quick thinker and problem solver.
Portfolio
Integrally LLC
JavaScript, HTML, CSS, jQuery, Git, OpenAI, OpenAIo1, LangChain, Google Cloud...
FrancklinCovey
Python, Docker, CI/CD Pipelines, Django, Pandas, NumPy, JSON, Bash Script...
Lorestry
React Native, Amazon Web Services (AWS), Infrastructure as Code (IaC), HTML5...
Experience
- Linux - 17 years
- PHP - 15 years
- APIs - 8 years
- Symfony - 6 years
- Amazon Web Services (AWS) - 4 years
- Docker - 4 years
- React - 3 years
- Magento 2 - 2 years
Work Experience
Senior Full-stack Engineer
2022 - PRESENT
Integrally LLC
- Implemented full-stack functionality, including user authentication, data ingestion pipelines, and custom API integrations using modern frameworks (e.g., React, Next.js, NestJS, and Python-based back-end services).
- Deployed advanced machine learning workflows, integrating ML pipelines with production systems to enhance intelligent data retrieval and semantic search.
- Leveraged Weaviate (vector database) to implement semantic search and context-aware recommendations, utilizing text embeddings and graph-based data modeling for high-performance querying.
- Optimized deployment infrastructure, containerizing applications with Docker and managing cloud deployment (e.g., AWS/GCP) to ensure high availability and maintainability.
Technologies: JavaScript, HTML, CSS, jQuery, Git, OpenAI, OpenAIo1, LangChain, Google Cloud, Pulumi, Weaviate, Neo4j, Artificial Intelligence (AI), Agentic AI, API Integration, Retrieval-augmented Generation (RAG), Full-stack Development
Senior Software Engineer
2022 - 2022
FrancklinCovey
- Developed the codespace environment for developers and new contractors to reduce the onboarding time.
- Moved downloadable content to secure S3 bucket links.
- Helped reunite multiple platforms into one single login interface.
- Developed new Django AWS S3 storage with synchronization between multiple buckets.
Technologies: Python, Docker, CI/CD Pipelines, Django, Pandas, NumPy, JSON, Bash Script, Web Development, Infrastructure, Full-stack, Web Frameworks, REST APIs, Git, PostgreSQL, API Integration, Full-stack Development
Full-stack Developer (React Native, JavaScript)
2022 - 2022
Lorestry
- Added features to the mobile application in React Native.
- Integrated Sentry to the React Native application.
- Developed the complete cloud infrastructure using the AWS Cloud Development Kit (AWS CDK) framework.
Technologies: React Native, Amazon Web Services (AWS), Infrastructure as Code (IaC), HTML5, SQL, JavaScript, CSS, HTML, DevOps, GitHub, Code Review, PostgreSQL, CI/CD Pipelines, Amazon EC2, JSON, Bash Script, AWS Fargate, Web Development, Infrastructure, Full-stack, REST APIs, Git, API Integration, Full-stack Development
React Developer
2022 - 2022
eMastered
- Developed user interface components and implemented them following well-known React workflows, such as Flux or Redux.
- Worked on AWS image optimization and processing, stored in AWS CloudFront CDN.
- Integrated Cypress.io end-to-end testing in the validation process for CI/CD pipeline.
Technologies: React, Express.js, Next.js, Amazon Web Services (AWS), Cypress, Jira, HTML5, SQL, MySQL, PHP 7, JavaScript, CSS, HTML, DevOps, React Router, Redux, GitHub, Code Review, Architecture, Laravel, CI/CD Pipelines, Microservices, Kubernetes, Jira REST API, JSON, Ajax, Bash Script, Postman, Web Development, Infrastructure, Full-stack, Web Frameworks, REST APIs, Git, Artificial Intelligence (AI), API Integration, Full-stack Development
Freelance Full-stack Developer
2020 - 2021
InvolveSoft
- Refactored and migrated all of the infrastructure from DigitalOcean to AWS using IaC.
- Divided the AWS infrastructure cost by 10 while keeping or improving the performance.
- Recreated the full CI/CD pipeline workflow using GitHub.
- Implemented Cypress.io from end-to-end and included it inside the CI/CD pipeline.
- Installed and configured Grafana monitoring tools for the client with a Slack integration.
- Integrated SSO with React as the front end and Python on the back end. The application is serverless and hosted in AWS.
Technologies: PHP, Amazon Web Services (AWS), Node.js, Python, Cypress, React, Redis, Serverless Architecture, Docker, Infrastructure as Code (IaC), TypeScript, Jira, HTML5, SQL, MySQL, PHP 7, JavaScript, CSS, HTML, DevOps, Bash, GitHub, Code Review, Architecture, CI/CD Pipelines, Azure, Bootstrap, Amazon EC2, JSON, Ajax, Bash Script, Postman, AWS Fargate, Web Development, Infrastructure, jQuery, Full-stack, Web Frameworks, REST APIs, Git, Large Language Models (LLMs), Prompt Engineering, Artificial Intelligence (AI), API Integration, Full-stack Development
Back-end Web Developer
2017 - 2020
Kathmandu
- Ensured good practice, CI integration, and new project integration.
- Headed the data migration from Magento 1 to Magento 2.
- Decoupled as many website features as possible into a serverless architecture, for example, in-store stock and Uber order delivery.
- Created a Magento feature for customers to create online orders in-store. The API feature has been integrated into almost 200 stores' POS systems.
- Handled the AWS infrastructure from Elastic Load Balancer to Dockerized infrastructure.
- Created a monitoring tool using Grafana. I hosted it in an AWS Fargate infrastructure.
Technologies: Amazon Web Services (AWS), PHP 7, Node.js, Neo4j, MySQL, APIs, Symfony, Grafana 2, React, PHP, Docker Compose, Docker, Linux, Sublime Text 3, Visual Studio Code (VS Code), Magento 2, Magento 1, Jira, HTML5, SQL, JavaScript, CSS, HTML, DevOps, React Router, Redux, Bash, GitHub, Code Review, Design Patterns, Architecture, CI/CD Pipelines, Microservices, Pandas, NumPy, Amazon EC2, Jira REST API, TensorFlow, JSON, Ajax, Bash Script, Postman, AWS Fargate, Web Development, Infrastructure, Magento, jQuery, PyTorch, API Connectors, Full-stack, Web Frameworks, REST APIs, Git, Artificial Intelligence (AI), API Integration, Full-stack Development
IT Director
2011 - 2015
Veditec
- Built a custom ERP solution for the organization using PHP.
- Developed an integration for four shipping methods in collaboration with partners.
- Designed and built a warehouse staff UI interface and optimization tool for the placement of products on shelves.
- Created SEO optimization tools for the marketing team.
Technologies: MySQL, APIs, Symfony, PHP, Makefile, Linux, PHP 7, Sublime Text 3, HTML5, SQL, CSS, HTML, DevOps, Bash, Architecture, Management, Material UI, JSON, Ajax, Bash Script, Web Development, Infrastructure, Doctrine, Yii, jQuery, API Connectors, Full-stack, Git, API Integration, Full-stack Development
Research and Development Developer
2009 - 2011
Visual-Link
- Improved a custom WYSIWYG CMS used by most of Visual-link's clients at the time.
- Developed an eCommerce website from scratch using CakePHP including a new payment method. The website was a full Flash application, and all user actions were API-based.
- Created the deployment process into servers for the CMS. The CMS product owned by the company was their main product and needed an easy deployment process in a new server with customization included (modules and plugins).
Technologies: MySQL, APIs, PHP, Makefile, Linux, Sublime Text 3, HTML5, SQL, CSS, HTML, DevOps, Bash, Code Review, Architecture, JSON, Ajax, Bash Script, Web Development, Infrastructure, Doctrine, jQuery, Full-stack, API Integration, Full-stack Development
Project History
Uber Delivery Integration
I contributed to the full integration of the Uber delivery service to enable the company to pursue product deliveries during the COVID-19 lockdown. The project delivery needed to be done in less than two weeks.
Requirements included:
* Checking availability of store stock
* Checking the distance between the customer and the closest store
* Checking the weight of the products
Requirements included:
* Checking availability of store stock
* Checking the distance between the customer and the closest store
* Checking the weight of the products
DigitalOcean to AWS Migration with AWS CDK
The migration included more than 20 servers from DigitalOcean to AWS. The entire infrastructure is implemented using AWS CDK, and so is the infrastructure as code. Each client has specificities that are configurable independently. The infrastructure is deployed using GitHub Actions.
Lorestry App
Lorestry creates useful lists and reports while recording activities and early events such as your child's first words, favorites, developmental milestones, and early life experiences.
I developed the complete cloud infrastructure using the AWS Cloud Development Kit (AWS CDK) framework.
I developed the complete cloud infrastructure using the AWS Cloud Development Kit (AWS CDK) framework.
Education
2002 - 2006
Master's Degree in Applied Mathematics
ENSIMAG - Grenoble, France
Certifications
SEPTEMBER 2021 - SEPTEMBER 2024
AWS Certified Developer - Associate
Amazon Web Services (AWS)
SEPTEMBER 2021 - SEPTEMBER 2024
AWS Certified Solutions Architect - Associate
Amazon Web Services (AWS)
FEBRUARY 2020 - PRESENT
AWS Innovate Machine Learning and AI Edition Certificate of Attendance
Amazon Web Services (AWS)
Skills
Libraries/APIs
React, Node.js, Doctrine, REST APIs, Jira REST API, jQuery, TensorFlow, PyTorch, React Router, Pandas, NumPy
Tools
Sublime Text 3, Jira, Composer, GitHub, Git, Postman, AWS Fargate, Docker Compose, Makefile, Amazon SageMaker, OpenAI Gym, Cheetah
Languages
PHP 7, PHP, Python, JavaScript, HTML5, SQL, HTML, Bash, CSS, Bash Script, TypeScript, C++
Frameworks
Symfony, Laravel, Django, Web Frameworks, Express.js, Next.js, React Native, Redux, Bootstrap, Material UI, Cypress, Yii
Paradigms
DevOps, Design Patterns, Management, Microservices, Serverless Architecture
Platforms
Magento 2, AWS Lambda, Linux, Docker, Amazon EC2, Amazon Web Services (AWS), Magento, Visual Studio Code (VS Code), Magento 1, Apache2, Azure, Kubernetes
Storage
MySQL, JSON, Neo4j, PostgreSQL, Redis, Amazon Aurora, Google Cloud
Other
APIs, API Connectors, Full-stack, Web Development, CI/CD Pipelines, Code Review, Architecture, Large Language Models (LLMs), Artificial Intelligence (AI), API Integration, Full-stack Development, Machine Learning, Grafana 2, Ajax, Infrastructure, Prompt Engineering, Agentic AI, Mathematics, Infrastructure as Code (IaC), Natural Language Processing (NLP), Generative Pre-trained Transformers (GPT), OpenAI, OpenAIo1, LangChain, Pulumi, Weaviate, Retrieval-augmented Generation (RAG)
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