Olivier Hoareau, Developer in Paris, France
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Olivier Hoareau

Verified Expert  in Engineering

Software Developer

Paris, France
Toptal Member Since
October 4, 2019

Olivier is an experienced full-stack hands-on tech leader. Over the last 15 years, he has worked as a freelancer with over 100 customers, mainly helping them bootstrap their platforms. Olivier is an expert on the back end, front end, and DevOps. He enjoys managing small teams consisting of one to 30 techs. He uses pair programming, code review, and architect meeting to motivate his colleagues. Olivier is autonomous and has been using agile practices and software craftsmanship since 2006.


Amazon Web Services (AWS), AWS Lambda, Terraform, React, GraphQL, Tailwind CSS...
AWS Lambda, Google Analytics API, Async/Await, REST, Amazon S3 (AWS S3)...
Amazon Web Services (AWS), AWS Lambda, React, Machine Learning, Python...




Preferred Environment

Node.js, WebStorm, GitHub, Git, MacOS, TypeScript, React, Amazon Web Services (AWS)

The most amazing...

...thing I've built is a complex cloud platform with 80+ projects that works on its own. I am proud that it is currently helping tens of nonprofit organizations.

Work Experience

CEO, CTO, and Co-founder

2021 - PRESENT
  • Designed the product and developed the platform that provides fundraising tools for nonprofit organizations and sports clubs in France, Europe, and beyond that want to modernize raffles, sell tickets online, draw winners automatically, and more.
  • Started the company, bootstrapped the tech platform, found first customers, and did business development.
  • Designed and built more than 80 microservices in TypeScript, Go, and Python, using custom-made code generators, more than 1,000 query operations in GraphQL, five GraphQL APIs, 40 REST APIs, asynchronous jobs, and event-driven architecture, fully serverless.
Technologies: Amazon Web Services (AWS), AWS Lambda, Terraform, React, GraphQL, Tailwind CSS, JSON Web Tokens (JWT), Amazon CloudFront CDN, Amazon Kinesis, Progressive Web Applications (PWA), SaaS, Web Architecture, API Architecture, Continuous Delivery (CD), Express.js, Node.js, CTO, Serverless, REST APIs, Test-driven Development (TDD), Stripe, JavaScript, Go, MUI (Material UI), Architecture

Senior DevOps Engineer and Back-end Developer

2022 - 2023
  • Designed a massively parallelized web page analysis platform to audit the carbon footprint of websites for the new startup, using open-source and custom-made back-end tools, all using the serverless infrastructure.
  • Tackled the Google Analytics API limits, analyzing more than 200 web pages in less than 45s.
  • Developed a zero-cost platform thanks to the serverless technologies that I used.
  • Mentored a young developer and worked on the business strategy with the CEO.
Technologies: AWS Lambda, Google Analytics API, Async/Await, REST, Amazon S3 (AWS S3), Node.js, TypeScript, PhantomJS, SaaS, Docker, Web Architecture, API Architecture, Continuous Delivery (CD), Express.js, Serverless, REST APIs, Stripe, Architecture

Mentor and Principal Architect

2020 - 2022
  • Designed the platform before the launch of the company with the CTO-to-be.
  • Developed the first components of the platform, scale to multiple microservices. Developed three admin web apps (an internal admin web app, merchant app, and bank web app), developed a custom-made "receipt matching" algorithm, and trained one to five developers in modern technologies.
  • Built a fintech platform with more than 10,000 transactions per hour using 100% serverless technologies and mastered the entire stack, including React components and Terraform IaC.
Technologies: Amazon Web Services (AWS), AWS Lambda, React, Machine Learning, Python, TypeScript, Node.js, MUI (Material UI), Amazon DynamoDB, Elasticsearch, Webhooks, Web Architecture, API Architecture, Continuous Delivery (CD), Express.js, CTO, Serverless, REST APIs, JavaScript, Architecture

Senior Full-stack Developer

2018 - 2020
  • Developed an eCommerce website and platform for this scaleup from scratch using modern technologies such as Gatsby, React, a headless CMS, and GraphQL.
  • Designed a UI design system with three UX designers over the course of six months. I also designed the implementation in React to be optimized for integration with Prismic's headless CMS.
  • Developed more than 500 React components single-handedly.
Technologies: React, Gatsby, Redux, GraphQL, Prismic, Amazon Web Services (AWS), AWS Lambda, Figma, Storybook, Web Architecture, Continuous Delivery (CD), Express.js, Serverless, REST APIs, JavaScript

Tech Lead and Mentor

2009 - 2020
  • Founded the company (freelance), found customers, and worked on-site in multiple regions in France and remotely.
  • Presented at French conferences on PHP best practices and industrialization.
  • Completed around 100 missions from SMB to international, mostly PHP and web technologies.
  • Served in a variety of roles, including those of a tech lead, lead developer, CTO, coach, architect, scrum master, and more.
  • Worked as a subcontractor for well-known IT architect consulting companies.
Technologies: Docker, Symfony, PHP, MongoDB, MySQL, Oracle, PHP 5, PHPUnit, Jenkins, Jira, REST APIs, Test-driven Development (TDD), Architecture

CTO and Co-founder

2014 - 2018
  • Co-founded the company from the idea to the production platform.
  • Designed and built various versions of the platform architecture.
  • Managed a tech team consisting of one to 17 techs, mostly remote freelancers.
  • Co-designed five products based on the same technical platform.
Technologies: React Native, Ionic, React, jQuery, NGINX, Varnish, Debian, MongoDB, Symfony, PHP, SaaS, API Architecture, Continuous Delivery (CD), CTO, Debian Linux, PHP 5, PHPUnit, Jenkins, Jira, Redis, Test-driven Development (TDD), Stripe, JavaScript, Architecture

Technical Expert/Architect

2007 - 2008
OCTO Technology (acquired by Accenture)
  • Designed and built application prototypes using Java and PHP.
  • Led the PHP offer, including pre-sales, prototypes, consultancy, and build.
  • Spoke at conferences. Worked for well-known French enterprises such as Orange, La Poste, Engie, and SFR.
Technologies: Java, PHP, PHP 5, XML, PHPUnit, Jenkins, Jira, Redis, Architecture

Project Manager

2006 - 2007
  • Managed the web portal of the main web platform. More than 100 web platforms are integrated with the portal.
  • Designed and reviewed the front partner integration kit (a JavaScript SDK).
  • Evolved in an ecosystem/portfolio of 100 platforms linked to the portal.
  • Managed providers, costs, delays, and planning. Worked in Belgium, Sweden, and Austria.
  • Wrote and reviewed functional and technical specifications.
Technologies: CSS, HTML, JavaScript, Servlet, Jakarta Server Pages (JSP), Java, Debian Linux, XML, Redis

Telecom Software Developer

2004 - 2006
  • Trained in the intelligent network field for a month.
  • Contributed as one of 100 worldwide engineers of the intelligent networks division.
  • Designed and built services on top of the Alcatel OSP platform (logic).
  • Managed accounts for various Alcatel customers in Europe.
  • Installed newly created services on-site for customers in Europe.
Technologies: Perl, C++, XML

Digital Raffle for Nonprofit Organizations

A web-based SaaS service for nonprofit organizations and sports clubs to launch a digital raffle. The service is available in 42 languages for small to international nonprofit organizations. It is integrated with Stripe Connect and PayPal.


Go, JavaScript, GraphQL, TypeScript, PHP 5, PHP 7, ECMAScript (ES6), XML, YAML, HTML5, Bash Script, PHP, SQL, Java, CSS, C++, Perl, Python 2, Python 3, Sass, HTML, CSS3, Python, TypeScript 3, ConTeXt


Jest, Express.js, Tailwind CSS, JSON Web Tokens (JWT), Symfony, Symfony 3, Symfony 4, PHP MVC, PHPUnit, YARN, Redux, Ionic, Jakarta Server Pages (JSP), React Native, Cypress, Swagger, Angular, Next.js, MUI (Material UI)


Node.js, React, REST APIs, Stripe API, Stripe, Jenkins Pipeline, Redux Form, Stripe Connect API, jQuery, ZeroMQ, TensorFlow, Redux-Saga, PayPal API, Context API, AWS Amplify, SendGrid API, Google Analytics API, PhantomJS


Terraform, Makefile, Lerna, Amazon CloudFront CDN, GitHub, Docker Hub, Docker Compose, AWS Simple Notification Service (SNS), Amazon Simple Queue Service (SQS), Make, CircleCI, Jenkins, AWS AppSync, AWS IAM, NPM, Yarn Workspaces, AWS Fargate, PHP-FPM, Varnish, NGINX, WebStorm, Behat, Puppet, Jira, Slack, Travis CI, Redux Thunk, Git, Servlet, Amazon Cognito, Cucumber, Ansible, Webpack, Expo, Gulp, Sketch, Amazon Elastic Container Registry (ECR), React Apollo, MQTT, GitLab, Figma


Test-driven Development (TDD), Continuous Integration (CI), Continuous Delivery (CD), Lambda Architecture, Scrum, Extreme Programming, Kanban, Behavior-driven Development (BDD), DevOps, Web Architecture, API Architecture, REST API Architecture, Microservices Architecture, REST


Amazon Web Services (AWS), Docker, AWS Lambda, Debian Linux, MacOS, Debian, Contentful, Firebase, Kubernetes, Amazon EC2, Zendesk, Web, Oracle


Amazon DynamoDB, Amazon S3 (AWS S3), MongoDB, NoSQL, JSON, Redis, Google Cloud, OVH, Memcached, MySQL, Elasticsearch


APIs, Storybook, Code Architecture, CTO, Serverless, Technical Leadership, Async/Await, Architecture, Gatsby, Lambda Functions, Widgets, SaaS, Private NPM Modules, Stripe Marketplace, Stripe Payments, Payment APIs, SMS, Keen.io, Amazon Kinesis, Coding, Algorithms, IT Project Management, Progressive Web Applications (PWA), Machine Learning, Webhooks, Prismic

1999 - 2004

Master's Degree in Computer Engineering

University of Technology of Compiègne (UTC) - Compiègne, Oise, France


AWS Solutions Architect Associate

Amazon Web Services


AWS Certified Developer – Associate

Amazon Web Services


AWS Certified Cloud Practitioner

Amazon Web Services


Structuring Machine Learning Projects



Improving Deep Neural Networks: Hyperparameter Tuning, Regularization, and Optimization



Neural Networks and Deep Learning