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William Da Silva AvelarWD

William Da Silva Avelar

Full-stack Developer

€450/day
Paris, FR
8-15 years

Average response time: 1 hour

Freelancer profile translated to English.
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About William

Need a reliable full-stack developer to build your web product, hassle-free?


With 10 years of experience in web development (front-end and back-end), I help entrepreneurs and SMEs transform their ideas into functional, fast, and scalable applications. Whether it's for a SaaS MVP, a custom dashboard, or a complex integration, I deliver concrete solutions within controlled timelines.

What you get:

  • Complete Full-stack: React/Vue, Node.js/Ruby on Rails, PostgreSQL/MySQL/MongoDB, Kubernetes
  • Product Experience: I've launched several personal SaaS projects (data platform, link-in-bio, directory). I understand business challenges, not just code.
  • Fast Delivery: I enjoy working in short cycles, with intermediate versions for validation.
  • Clear Communication: Everything is done in writing (messages, tickets, documentation), for perfect traceability.

My typical projects:

  • High-converting landing pages + admin backoffice
  • SaaS MVP (auth, dashboard, payments, API)
  • Third-party API and data system integrations
  • Refactoring and modernization of existing applications
  • Infrastructure deployment and configuration (DevOps)

I am available for freelance missions or long-term technical support. Let's discuss your project.
  • French

    Native or bilingual

  • Portuguese

    Native or bilingual

  • English

    Fluent

Can work on-site
Paris (up to 50km)

Experience

  • Direction générale des finances publiques
    Full-stack Developer
    PUBLIC SECTOR
    March 2023 - November 2025 (2 years and 8 months)
    Paris, France
    During my 2 years at DGFiP, I worked on a web-builder using VueJS, GrapesJS, and NodeJS for the DTNum. My responsibilities included:
    • Front-end development in VueJS / GrapesJS and back-end (Node.js / Prisma, Socket.io, PostgreSQL) of the platform
    • Ensuring compliance with the portal's and editor's accessibility rules
    • End-to-end design of the application architecture
    • Collaborating with the development team, the infrastructure team, UX designers, and the project owner to ensure platform consistency
    • Handling Ops on Cloud Nubo (Ansible, Terraform, OpenStack)
    • Organizing and leading technical meetings with the team
    Vue.js Node.js Prisma Socket.io PostgreSQL
  • Chronotruck
    Front-end Developer
    TRANSPORTATION
    June 2018 - December 2022 (4 years and 6 months)
    Paris, France
    When I joined Chronotruck, I was responsible for a VueJS SPA in collaboration with another front-end developer, a few back-end developers, and a product team. We developed our features using agile methodologies, applied fixes with the help of Sentry, and utilized our advanced testing stack (Vitest, Puppeteer, Nightwatch, BrowserStack).

    I had the opportunity to implement our CI/CD pipeline with CircleCI and then Github Action. DevOps tasks were also performed to improve our Capistrano deployments, Docker images, and the development of Terraform/Ansible scripts.

    During my 4 years, I mentored front-end interns, collaborated with new front-end developers, and worked with external teams on new projects.
    Vue.js Vitest Bootstrap Puppeteer BrowserStack
  • My Cuistot
    Full-stack Developer
    RESTAURANTS AND FOOD SERVICE
    June 2016 - June 2018 (2 years)
    Paris, France
    Joining a team of 3 developers, I was in charge of continuing the design of the backend architecture for the platform in Ruby on Rails.

    Later, I had the opportunity to work on the platform's Android and iOS application using AngularJS & Ionic. This mobile application would later be rewritten in React Native.

    In addition, I designed the interface on Figma in collaboration with the product team and integrated the new platform in VueJS/Nuxt, partly using VueMaterial and then Vuetify.
    Nuxt.js Vue.js Ruby on Rails PostgreSQL AngularJS

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Education

  • Baccalaureate
    Lycée Albert Schweitzer
    2016
    Baccalauréat

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