Osny Netto
Verified Expert in Engineering
JavaScript Developer
Florianópolis - State of Santa Catarina, Brazil
Toptal member since April 29, 2019
Osny is a full-stack engineer with over 15 years of experience building web and mobile products. He focuses primarily on front-end development, product experience, and the design details that make software feel clear and easy to use. He works with tools like Claude Code, Cursor, and Codex to prototype, debug, refactor, and iterate faster while keeping the codebase maintainable. His strength is turning complex ideas into fast, thoughtful user interfaces and practical end-to-end systems.
Portfolio
Experience
- JavaScript - 13 years
- UI Design - 13 years
- UX Design - 13 years
- HTML - 13 years
- CSS - 13 years
- React - 10 years
- Sketch - 5 years
- Ruby on Rails (RoR) - 4 years
Preferred Environment
Slack, ITerm, Git, MacOS, Cursor AI, Figma, QR Codes, CTO, Codex, Redis
The most amazing...
...thing was building a self-service Chrome extension that let non-technical users create guided website tours, helping the product grow to over 300 customers.
Work Experience
Senior Software Engineer
Memori
- Built the first version of the frame builder that increased conversion rate from 4% to 5%, a 25% improvement in purchase conversion.
- Built responsive, accessible UI components using React and TypeScript across the Collection, Product Detail, and Cart pages, ensuring cross-device consistency aligned with the company's design system.
- Implemented 3D product thumbnails on the Collection pages to better illustrate the final product with custom photos applied, increasing product click-through rate by at least 20%.
- Used AI-assisted development workflows with Claude Code, Cursor, and Codex to accelerate React and TypeScript implementation, rapidly iterate on UI details, and maintain high-quality production code across eCommerce product flows.
Senior Full-stack Engineer
Praxis Labs
- Designed a new bulk import interface that reduced user onboarding time by 90%, replacing a manual process with a streamlined self-service flow for thousands of users.
- Improved the learning platform UI by simplifying navigation and refining layouts, which increased user engagement by 15% across key flows.
- Architected and built the initial platform version in three months using React, GraphQL, and Ruby on Rails, establishing the core technical foundation.
- Leveraged LLM-assisted workflows to prototype features, refine GraphQL/Rails implementation details, generate test coverage, and compress delivery cycles while building the initial platform under a tight three-month timeline.
Senior Full-stack Engineer
ChangeX
- Proposed and implemented a standalone React dashboard, decoupling the front end from the Ruby on Rails monolith and reducing deployment cycles from months to days with an 80%+ decrease in deploy time.
- Led a full website redesign that strengthened the platform's professional tone with partners and improved the application flow, resulting in more qualified applicants for social innovation programs.
- Managed a team of five engineers, overseeing technical decisions, code reviews, and sprint planning while balancing hands-on development with team leadership.
- Applied AI-assisted refactoring and debugging workflows while decoupling the React front end from the Rails monolith, helping modernize legacy code, reduce deployment friction, and support faster iteration.
Senior Front-end Engineer/UI Engineer
Joybird
- Built and maintained a 30+ component React UI library as the sole front-end engineer, ensuring pixel-perfect, cross-browser consistency across the entire eCommerce platform.
- Collaborated with a 7-member team on a year-long migration of the eCommerce platform to React and Next.js with a headless CMS, building a flexible page generation system that enabled content teams to create new pages without engineering involvement.
- Developed highly extensible, reusable components that accelerated feature development and improved site performance, enabling a faster and more consistent shopping experience for thousands of daily visitors.
Senior Front-end Developer (User Onboarding)
Conpass
- Developed and designed a Google Chrome Extension using React and Redux, growing the client base from 10 to over 400 during tenure.
- Built and maintained the API and web application using Node.js, serving as the second engineer on the team and helping scale the engineering team to 10.
- Engineered a cross-browser, lightweight pixel tracking code (injectable JavaScript) deployed across 400+ client websites, handling millions of requests daily across multiple pages and placements.
- Designed a 100% self-service onboarding product that allowed clients to create flows, generate installation code, and deploy without engineering support, enabling the company to scale rapidly without increasing headcount.
Front-end Developer & UI/UX Designer
CIMM
- Upgraded the main product through two major Rails migrations (Rails 2 to 3, then to 4), improving overall website performance by over 40% based on client-side and server-side monitoring.
- Grew monthly organic traffic from 150,000 to 480,000 visits on the main portal through a self-initiated on-page SEO strategy, leveraging deep involvement in the digital marketing community.
- Set up cloud infrastructure on Rackspace and automated deployment pipelines using Capistrano and development environments using Vagrant, enabling the team to scale and ship faster.
- Prototyped high-quality UI designs and developed responsive frontends for a high-traffic portal serving thousands of daily visitors over an 8-year tenure.
- Maintained and developed multiple websites using WordPress and Ruby on Rails, handling both front-end development and back-end architecture.
Front-end Developer | UI Designer
Filmow
- Redesigned the most visited pages—helping the users to accomplish crucial actions.
- Collaborated with other team members using tools like Mercurial, Jira, and Bitbucket.
Developer | Designer
Instituto Stela
- Improved the UI of some of the company's major products such as the Stela Experta and Aquarius platforms.
- Developed an internal website using Liferay to help the team to keep updated about processes and activities.
- Built and maintained websites using WordPress and Joomla.
Web Designer | Developer
Jimmy FFW
- Created the UI design and developed the front-end.
- Developed websites with WordPress and Joomla.
- Built web apps using Ruby on Rails and PHP.
Web Designer | Developer
FabriCO
- Created custom themes for an LMS system (Moodle).
- Designed and developed the company's website.
- Helped the team to create and deliver EAD platforms.
Experience
Conpass
GitHub
Joybird
Quintal de Trocas
https://github.com/baobba/quintal-de-trocasAirfocus
https://airfocus.com/Education
Associate's Degree in Graphic Design
Universidade do Vale do Itajaí - Florianópolis, Brazil
Skills
Libraries/APIs
Node.js, React, JSON API, Flexbox, Claude API, Vue, REST APIs, React Redux, jQuery, Ruby ERB, Stripe, OpenAI API, Three.js, React Navigation, OpenAPI
Tools
GitHub, ITerm, Slack, Sketch, Git, JSX, Figma, Claude Code, ChatGPT, Claude, Jira, Confluence, NPM, Webpack, Babel, React Apollo, Google Analytics, Shadcn, Expo, Sentry, Codex, Moodle
Languages
HTML, JavaScript, CSS, HTML5, TypeScript, Sass, CSS3, ECMAScript (ES6), SCSS, Python, PHP, GraphQL, Ruby, Haml, SQL
Frameworks
Next.js, React Native, Material UI, Tailwind CSS, Cypress, Ruby on Rails (RoR), Jest, Redux, Bootstrap, Express.js, Slim, Fastify, Ruby on Rails 7
Paradigms
Responsive, UI Design, On-page SEO, UX Design, REST, Search Engine Optimization (SEO), Conversion Rate Optimization (CRO), Responsive Web Design (RWD), Automated Testing, Design Patterns, Mobile Design, Best Practices, Mobile UI Design, RESTful Development, Agile, Test-driven Development (TDD), Agile Software Development, Scrum, Model Context Protocol (MCP), Responsive Coding
Platforms
Webflow, MacOS, WordPress, Vercel, Replit, Mixpanel, Heroku, Amazon Web Services (AWS), Linux, Docker, iOS, Google Cloud Platform (GCP), Visual Studio Code (VS Code), Firebase, Joomla
Industry Expertise
Web Design, Project Management
Storage
MySQL, MongoDB, PostgreSQL, Amazon S3 (AWS S3), SQLite, Redis
Other
Web Development, SaaS, Front-end, User Experience (UX), User Interface (UI), Front-end Design, Full-stack, APIs, Single-page Applications (SPAs), Web UI, Pixel Perfect, CSS Grid, Styled-components, Styling, Material Design, Dashboard Development, Cross-browser Testing, Data Visualization, PSD Slicing, Code Review, AI Agents, Software Engineering, Software Integration, UI Components, Performance Optimization, Cursor AI, Artificial Intelligence (AI), AI Tools, Full-stack Development, Software Architecture, Vibe Coding, Payments, Figma to React, Tailwind UI, Mobile First, AI Design, AI Programming, Page Speed Optimization, Agentic AI, UI Animation, High-end Design, User Experience Design, Front-end Development, Anthropic, Chrome Extensions, DOM, Design Systems, Front-end Architecture, Dashboards, Prompt Engineering, AI Engineering, UI Engineering, eCommerce, Gatsby, Back-end, Apollo, CSS3 Animation, SVG, Apollo Server, Security, Retrieval-augmented Generation (RAG), AI Integration, OpenAI, API Integration, IT Project Management, AI-generated Code, Supabase, Vite, Supabase Auth, CTO, Gemini, Payment APIs, Application State Management, CI/CD Pipelines, Architecture, Fractional CTO, Technical Leadership, Large Language Models (LLMs), FastAPI, Animation, Migration, Legacy Code, Scaling, Leadership, Browser Automation, Data Scraping, Content Management Systems (CMS), Design, Responsive UI, Storybook, Data Analytics, Financials, QR Codes, Railway
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