
Matheus Brehm Barni
Verified Expert in Engineering
JavaScript Developer
Santa Catarina, Brazil
Toptal member since September 8, 2026
Matheus is a senior front-end and full-stack engineer with over five years of experience building scalable web and mobile applications for clients, including Digibee, Arctouch, and CVC Corp. His primary expertise is in React, TypeScript, and Node.js for the technology and media industries, where Matheus thrives in Agile, cross-functional teams. He reduced travel-package creation time by over 90% while at CVC Corp.
Portfolio
Experience
- React - 8 years
- JavaScript - 8 years
- TypeScript - 8 years
- Java - 6 years
- Node.js - 6 years
- Spring Boot - 6 years
- React Native - 4 years
- Go - 4 years
Preferred Environment
MySQL, Git, CI/CD Pipelines, Java, JavaScript, TypeScript, Node.js, React, React Native, Go
The most amazing...
...application I've built is a high-performance package-builder that reduced travel-package creation time from three days to under two hours.
Work Experience
Senior Software Engineer
Digibee
- Drove a serverless consumption-plan initiative for Digibee’s enterprise integration platform, improving platform scalability and cost-efficiency.
- Extended the company-wide React and TypeScript design system, improving component reuse and UI consistency across products.
- Implemented governance and compliance controls to improve platform reliability and integration quality.
Senior Software Engineer (Contract)
Loopia
- Built a React Native application powering chat-commerce flows across WhatsApp and social platforms, integrating AI-agent and marketplace APIs.
- Delivered a TypeScript React Native app that let marketplace sellers handle product questions, shipments, and customer messages from their phones.
- Extended Loopia's seller platform to mobile, giving store owners a phone-first way to run chat-commerce instead of depending on the desktop product.
- Shipped production React Native and TypeScript features in a three-month contract, covering chat-commerce from messaging through automated ordering.
Senior Software Engineer (Contract)
An Online Freelance Agency
- Delivered React and SCSS UI components for a weather-tech client, integrated with Node.js back-end services in a distributed cross-border team.
- Collaborated with a distributed cross-border team across time zones, using async standups and written updates to ship React work without blocking partners.
- Built reusable React and SCSS UI components for a weather-tech client and fitted them into the existing product front end.
- Shipped production React, SCSS, and Node.js front-end work over a five-month period with an online freelance agency contract for a weather-tech product team.
Software Engineer
ArcTouch
- Built back-end services for Disney Media (DMED) using Java, Quarkus, and AWS, optimizing ETL pipelines and improving data throughput.
- Delivered full-stack features for global clients using React, Next.js, Node.js, and Go across web applications and data pipelines.
- Built an internal team-allocation tool that centralized employee skills and project-history tracking, improving allocation efficiency.
Software Engineer (Freelance)
One Ticket
- Built a self-service ticketing kiosk application with Tauri and React for a native desktop experience.
- Engineered ticket-selection, seat-reservation, and checkout flows in Next.js with optimized state management.
- Implemented seat-map selection with optimized React state so choosing a seat did not re-render the entire ticketing UI.
- Delivered ticket-selection, reservation, and checkout across Tauri kiosk and Next.js flows over a two-year freelance engagement.
Software Engineer
CVC Corp
- Reduced travel-package creation time from two to three days to one to two hours by building a high-performance package-builder application with Next.js and React.
- Integrated airline, hotel, concert, and other internal services into a unified package-creation workflow, reducing manual cross-system steps.
- Established reusable UI components and automated test coverage with Storybook and Jest, improving consistency and reducing regressions.
Software Engineer (Mobile)
Leader Aplicativos
- Shipped over 10 cross-platform mobile applications to the App Store and Google Play, including Robomind+, a robotics-education app.
- Built shared React Native components and Node.js integrations reused across client applications, accelerating delivery of new builds.
- Delivered Robomind+ for robotics education on iOS and Android, taking a React Native app through App Store and Google Play release.
- Shipped production React Native and Node.js mobile work over a 10-month role, releasing client apps to both app stores.
Software Engineer
Demacode (now Smolla)
- Built custom real-estate and eCommerce web applications for startups and SMBs using React, Node.js, and Java.
- Developed responsive, full-stack features and back-end APIs from requirements through production delivery.
- Wrote Node.js and Java back-end APIs that supported custom React web apps for real-estate and eCommerce clients.
- Shipped production full-stack features over a two-year role, covering responsive UI and API work for startup and SMB clients.
Experience
Compozy
https://github.com/compozy/compozyI contributed as an open-source engineer on the task runner and operator UX. I added multi-task run support and worktree-backed parallel runs so several tasks could execute at once without colliding. I also shipped provider-neutral ACP speed control, recovered stalled and wedged multi-runs, restored TUI elapsed timers across retry, failure, cancel, and remote paths, and fixed Claude model pinning plus zsh task completion so operators could run and complete tasks more reliably from the CLI.
Idle Manager
https://github.com/MatheusBBarni/idle-managerI designed and built the product end-to-end in Electron and React. The chrome is React; each running account is a native WebContentsView bound to a persistent partition. I implemented tab and account layouts; per-account mute, zoom, and reload; live CPU and RAM in the sidebar; workspace import/export of names and URLs only; optional safeStorage encryption; keyboard shortcuts; and PT/EN. I also added an isolation test that proves two partitions do not share cookies or localStorage, and I ship Windows, macOS, and Linux installers through GitHub Actions. The app does not automate gameplay or inject cheats.
Spec Finder
https://github.com/MatheusBBarni/spec-finderI designed and built the product as a Bun/TypeScript CLI and published it on npm. I implemented the setup across five ACP providers, a read-only cockpit for provider configuration, task graph, and tool calls, one ACP session per task, so implementation and the final report share context, serial fail-fast batch runs, local recovery checkpoints that never push, and an optional TDD pack for red-before-green work. Skills stay portable, and the framework does not install provider binaries or store credentials.
Education
Coursework Toward a Bachelor's Degree in Information Systems
Estácio - Brusque, SC, Brazil
Certifications
AI for Developers
Branas.io
Skills
Libraries/APIs
React, Node.js, D3.js
Tools
Git, Claude, Claude Code, Codex
Languages
TypeScript, JavaScript, HTML, CSS, Go, Java, Rust, PHP
Frameworks
Tailwind CSS, Next.js, React Native, Tauri, Jest, Redux, Spring Boot, Electron
Paradigms
Agile, Scrum, Kanban, DevOps, Microservices, Functional Programming
Platforms
Docker, Kubernetes
Storage
MySQL
Other
Quarkus, Storybook, CI/CD Pipelines, Design Systems, ETL Pipelines, Compilers, Software Development, Bun, Terminal UI, Command-line Interface (CLI), AI, Spec-drive development
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