Justin Villalpando
Verified Expert in Engineering
Front-end Developer
Elsa, TX, United States
Toptal member since May 16, 2022
Justin is a senior front-end architect with a broad and deep technological foundation. Over the last 10 years, he gained experience dealing with diverse tasks and challenging problems, including building front-end infrastructures and designing and optimizing numerous projects. Justin focuses on developing complete solutions from the ground up using modern JavaScript frameworks and blockchain technologies.
Portfolio
Experience
Availability
Preferred Environment
Visual Studio Code (VS Code), Slack, Jira, Server-side Rendering (SSR), Charts, REST APIs, JavaScript Testing, Responsive Design, Accessibility, Sass, TypeScript
The most amazing...
...thing I've developed was the NFT marketplace called Axie Infinity with 600,000+ users.
Work Experience
Front-end React Developer
DocuSign Inc - Main
- Worked on reskinning the marketing platform according to the new design system and migrated Drupal 7 web contents into Contentful.
- Built new reusable calligraphy components under atomic design pattern and pattern library components that interact with Contentful data.
- Fixed some important production issues while working closely with customers and stakeholders, boosting the user experience to the next level.
Senior Front-end Engineer
Airbnb
- Developed Pineapple, the world's most popular app for vacation homes and condo rentals, working as a senior front-end engineer.
- Wrote unit testing using Jest and RTR on Storybook variations and E2E testing with Cypress, boosting test coverage by over 95%.
- Worked on micro-frontend architecture for a monolithic front-end app, enabling the development of scalable and modular front-end systems.
- Implemented data obfuscation functionality on the personal information page, enhancing security measures and accessibility.
- Contributed to internationalization, supporting multiple languages and creating comprehensive technical documentation.
- Fixed some customer-affecting production issues in the tight deadline, working closely with the customers and support team directly.
Senior Front-end Engineer
Netflix
- Developed Ozark-UI, a supplier onboarding platform for Netflix using React, Context API, Hawkins—Netflix's internal UI framework—, DataGrid, Karbon for E2E testing, etc.
- Built the reusable components using Hawkins and provided descriptive documentation with the examples in the storybook.
- Troubleshot some important production bugs, boosted performance and code quality to the next level, and contributed to internationalization.
Senior Front-end Engineer
Sky Mavis
- Developed a blockchain-based NFT marketplace platform using React, Redux Toolkit, TypeScrpit, MUI, Storybook, Ethers.js, and MetaMask.
- Introduced an atomic design with descriptive documentation using Storybook and configured its UI library and design system on the top of MUI using all the reusable components like atoms, molecules, and organisms.
- Implemented breeding, hatching, buying, and selling functionalities leveraging Ethers.js blockchain technology.
- Built a user-friendly filtering functionality and boosted the code quality and performance significantly.
Front-end Tech Lead
Scriber
- Developed the all-in-one publishing tool for finance writers using React, Redux Toolkit, TypeScript, Next.js, Recharts, Tailwind CSS for styling, Apollo GraphQL, Cypress.io for E2E testing, AWS Amplify, and Storybook.
- Acted as the front-end tech lead, mentored junior developers, and participated in making technical decisions at a high level.
- Implemented an app authorization and data integration such as query and subscription using AWS Amplify and Apollo GraphQL.
- Introduced a micro front-end architecture decomposing the project into individual and semi-independent micro apps working closely together.
- Built the data visualization using Recharts and applied Storybook to expose reusable components with descriptive documentation.
- Wrote the E2E test scripts using Cypress.io and boosted test coverage by over 90%.
Senior Front-end Engineer
VIVANT
- Developed a virtual wine tasting platform using React, Redux Thunk, Socket.IO, LogRocket, Sentry, and SCSS.
- Built various complex live session components focusing on maintainability and testability.
- Implemented the lobby and wine tasting session screens utilizing Socket.IO and boosted user experience by introducing user-friendly animations and building mobile versions.
- Followed the Scrum methodology using Asana while collaborating closely with the UX design and back-end teams.
Senior Front-end Engineer
Garden.io
- Developed a marketing platform for Garden, which provides end-to-end development and testing services for Kubernetes and cloud using React, Gatsby, TypeScript, Apollo GraphQL, Emotion, and Markdown.
- Implemented the blog posts and details pages using Apollo GraphQL, Contentful, and Markdown.
- Boosted the project infrastructure, optimizing the performance and enhancing code quality to the next level.
- Fixed some critical user experience issues on both desktop and mobile screens UI, keeping consistency across the different browsers.
Front-end Engineer
Cognitus Consulting
- Oversaw the building of pixel-perfect and mobile-friendly UI/UX of various web applications and API integrations.
- Improved the design and performance of writing the code in a high-paced and challenging environment, emphasizing the best practices.
- Worked actively in Agile and Scrum environments with 2-week sprints.
Experience
Axie Infinity | NFT Marketplace
I developed it using React, Redux Toolkit, Material UI, Storybook, Ethers.js, and MetaMask. I also introduced an atomic design with descriptive documentation using Storybook and configured its UI library and design system on the top of Material UI. With the user-friendly filtering functionality and improved code, the performance was boosted significantly.
Scriber | Publishing Tool for Finance Writers
https://scriber.toAs a front-end lead, I developed it using React, Redux Toolkit, TypeScript, Next.js, Recharts, Tailwind CSS for styling, GraphQL, Cypress.io for E2E testing, AWS Amplify, and Storybook. I also implemented an app authorization and data integration, introduced a micro-frontend architecture, built the data visualization, wrote E2E test scripts, and boosted test coverage by 90%.
VIVANT | Virtual Wine Tasting and Organic Wine
https://vivant.eco/I built complex live session components while ensuring maintainability and testability, implemented the lobby and wine tasting session screens, and introduced user-friendly animations and mobile versions, improving user experience.
Garden.io | Market Platform
https://garden.io/I developed it with React, Gatsby, TypeScript, GraphQL, Emotion, and Markdown, implemented the blog posts and details pages, boosted the project infrastructure, optimized the performance, and enhanced code quality. I also fixed critical user experience issues on desktop and mobile UI, keeping consistency across the different browsers.
ATD Org | Education and E-learning Platform
https://td.orgI built this platform using React, Apollo GraphQL, TypeScript, Material UI, and Algolia, leveraging an atomic design. Built a reusable ATD component library using React, Material UI, TypeScript, and Styleguidist and published them into the cloud using bit.dev. Worked on TDD strategy writing testing scripts using Jest/Enzyme.
Heycar | Car Marketplace
https://heycar.comI worked as a founding front-end engineer at Heycar, building a car marketplace platform from scratch using React, Next.js, TypeScript, and Storybook, and contributed to architecting the project structure. Wrote unit testing using React testing library and implemented internationalization using the React-intl library. Built reusable components and exposed the examples in the storybook, and developed a bunch of custom hooks for various purposes.
EdLight | Education and Feedback Platform
http://edlight.comAs a senior front-end engineer, I contributed to building the EdLight MVP app within a tight deadline. I updated the storybook configuration to adapt Webpack 5 and the latest node version and refactored CSS module files to maintain consistency across the app. I also built a planner calendar component with dot indicators utilizing the MUI library.
Education
Master's Degree in Computer Science
The University of Texas at Austin - Austin, Texas, USA
Certifications
React Certified Engineer
Sololearn
JavaScript Certified Engineer
Sololearn
Skills
Libraries/APIs
React.js, Emotion Library, Context API, Node.js, React.js, Stripe Development, REST API, AWS Amplify, Web3.js, React Testing Library, D3.js, Highcharts, Chart.js, JavaScript, WebRTC, React Hook Form, Recharts, React Query, Formik
Tools
Figma, Git, GitHub, NPM, Jira, Redux Toolkit, MetaMask, Webpack, Amazon Cognito, WebdriverIO
Languages
TypeScript, GraphQL, SCSS, Markdown, JavaScript, HTML5, CSS3, HTML, CSS, Sass, Python, PHP, SQL
Frameworks
Material UI, Redux, Next.js, Ant Design, Bootstrap, Cypress, Jest, Tailwind CSS, Express.js, NestJS, Django, Flask
Paradigms
Unit Testing, Responsive Web Design, SEO, E2E Testing, Agile Development, UX Development, UI Design
Platforms
Vercel, Blockchain, Docker, AWS, Contentful, Cloud Engineering, Kubernetes, Heroku, Azure, Drupal Design, Netlify
Storage
PostgreSQL, MongoDB, Redis, MySQL
Other
Storybook, Atomic Design, Data Visualization, GatsbyJS, Front-end Development, Styled-components, Semantic UI, React Hooks, UI Development, UX Development, Server-side Rendering (SSR), Charts, Chakra UI, Responsive Design, APIs, Responsive Web Development, Front-end, Startup Development, Architecture, Technical Leadership, Web Development, Single-page Applications (SPAs), Progressive Web Applications (PWAs), Pixel Perfect, CSS Modules, Headless CMS, Web UX Design, Memory Optimization, Performance Optimization, Figma to React, Cloud Services, Ethers.js, Front-end Architecture, Enzyme, CSS-in-JS, Animation Development, Accessibility Development, Apollo, NFT, SDKs, People Management, Material Design, Tailwind UI, Minimum Viable Product (MVP), Ajax, WebSockets, SSO Engineering, Fintech Development, Full-stack, XState, Monorepos, ESLint, Internalization, Netflix Hawkins, DataGrid, Internationalization
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