Júlio Carneiro

Senior Frontend Engineer

I build interfaces that perform. Fifteen years through newsrooms, hosting, FinTech, health, and Web3 — always at the intersection of software engineering and visual design.

Currently at VoA, architecting the frontend v3. Graphic Design education and 3D modeling background — I see product through a designer's eye and build through an engineer's.

Medium Dev.to TryHackMe ArtStation

About

I started building for the web in 2009, at Folha de S.Paulo. Fifteen years, several companies, a few failures, and many products that reached millions of people.

Graphic Design education and years of 3D modeling changed how I see the screen — not as a canvas of components, but as a visual space with intention. That lens is what makes my collaboration with UX/UI teams different.

Along the way, I architected e-commerce frontends that directly impacted revenue across Latin America, hit 100/100 on PageSpeed for Mitsubishi, delivered 100% test coverage at Munchies, and built Web3 platforms from scratch. Each project left a layer.

I contribute to the community by writing about frontend, mobile, and automation. I created open source libraries — ChordKit and TabKit — because I believe good tools multiply good products.

I believe good code is invisible. The user doesn't notice — and that's exactly the point.

15+

years of experience

100

Google PageSpeed

SaaS · FinTech · Health · Web3

sectors served

Design + Engineering

multidisciplinary background

Experience

Nov 2023 — Present·VoA

Senior Frontend Engineer

Led frontend architecture evolution using Next.js, React, and TypeScript for high-performance scalable applications. Built a real-time collaborative editing platform with LiveBlocks and Tiptap, and a Headless CMS that empowered the Marketing team to manage content independently. Achieved a perfect 100 score on Google PageSpeed for key pages. Delivered React Native mobile apps for real-time voice transcription and AI-powered medical assistance.

Next.jsTypeScriptReact NativeZustandLiveBlocksTiptapDockerCI/CD

Dec 2022 — Oct 2023·Munchies

Frontend Engineer (Web3)

Designed the frontend architecture for a Web3 platform using Wagmi and Ethers.js for smart contract interactions. Achieved 100% unit test coverage with Jest and React Testing Library following strict GitFlow processes. Improved client efficiency through GraphQL and Apollo integrations, reducing data overhead.

Next.jsTypeScriptWeb3WagmiEthers.jsGraphQLApolloJest

Jul 2021 — Dec 2022·HostGator América Latina

Senior Frontend Engineer

Maintained and evolved critical conversion flows — Checkout, Cart, Client Area, and Chat — directly impacting revenue across Latin America. Collaborated with Product Managers and Designers to improve user experience at scale, delivering robust solutions with React, Next.js, and TypeScript.

Next.jsTypeScriptRedux/SagaDockerJestStorybookCI/CD

Aug 2020 — Jul 2021·Mobiauto

Front-end Engineer

Architected the new Mitsubishi Motors Brazil website with a focus on performance and SEO using Next.js and TypeScript. Developed an internal Chrome extension to compare PageSpeed results between development and master environments.

Next.jsTypeScriptPreactContext APIJestCypressStorybook

Sep 2019 — Aug 2020·gal, salon (LaPag)

Front-end Engineer

Developed the static website and help center blog using Gatsby, ensuring high performance and SEO. Built new features for the Lapag/Gal system using Meteor, React, and Styled Components.

GatsbyReactMeteorStyled ComponentsReduxTypeScript

Sep 2018 — Sep 2019·Pixter

React Developer

Responsible for architecting a scalable system for Porto Seguro using React, Redux, and Firebase. Focused on code organization, scalability, and integration with third-party services.

ReactReduxFirebaseStyled ComponentsCypress

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