Guangxi Jin
Verified Expert in Engineering
Full-stack Developer
Singapore, Singapore
Toptal member since March 31, 2022
Guangxi is an experienced full-stack developer with 10 years of experience in API/web front-end/mobile app development, DevOps, AI, and blockchain. He's built several successful websites, mobile apps, and DeFi platforms with hundreds of thousands of users while working as a senior developer, lead developer, or product manager. Following clients' business ideas, Guangxi has completed over 10 projects involving various technological fields from scratch. He values honor, integrity, and teamwork.
Portfolio
Experience
Availability
Preferred Environment
MacOS, Linux, Visual Studio Code (VS Code), GitHub, Bitbucket, GitLab, LAMP, Git, CI/CD Pipelines, Mobile App Development, Android Studio, Xcode, DevOps, Rust, Docker, Minimum Viable Product (MVP), Web3, Web Development, Tailwind CSS, Artificial Intelligence (AI), Azure, Cloud, Full-stack Development, Machine Learning, Python, Express.js, TensorFlow, Go, Python 3, React, JSON, Test-driven Development (TDD), JavaScript Testing, Mobile First, Mocha, Cloud Platforms, Documentation, SwiftUI, TypeScript, Next.js, AWS Lambda, Flutter, Cross-platform, Mobile Applications, Vue, Front-end Development, Google Cloud, Object-oriented Programming (OOP), GraphQL, NGINX, Socket.IO, Containerization, Responsive Web Design (RWD), Responsive Web Apps, CSS, CSV, Data Visualization, JavaScript 6, Mathematics, Graphs, Trading, SEO Tools, Storybook, Responsive Design, Cross-browser Compatibility, Unit Testing, NestJS, Architecture, New Product Development, Database Administration (DBA), Object-relational Mapping (ORM), ECMAScript (ES6), Mongoose, Vuetify, WebSockets, OAuth 2, Mobile Development, Sass, Kotlin, Node.js, Solana, Async/Await, GitHub Workflows, SEO Marketing, React Native, Back-end Development, Distributed Systems, Generative Pre-trained Transformers (GPT), Generative Pre-trained Transformer 3 (GPT-3), Software Development, Atlassian, Leadership, Client Relationship Management, Integration, Decentralized Finance (DeFi), Solidity, Crypto, Data Science, Prisma, Amazon DynamoDB, Infrastructure as Code (IaC), AWS Cloud Architecture, FastAPI, Terraform, Game Development, Sockets, Pandas, Data Analysis, Asynchronous I/O, tRPC, Cryptocurrency
The most amazing...
...mobile app I've developed is a music radio player called Vybn, which received more than 10,000 daily users within a month after deployment to app stores.
Work Experience
Lead Full-stack Engineer
Hive Social Inc.
- Developed a mobile social app, resulting in over 500,000 downloads in the first month.
- Got the business ideas and graphic designs from the CEO and the designer and updated them according to technical needs.
- Built version 1 of the mobile app (iOS) with Swift and UIKit.
- Built version 2 of the mobile app (iOS and Android) with Flutter.
- Created Firebase Firestore collections and security rules.
- Wrote Firebase functions for the back-end triggers and complex Firestore queries.
- Built and deployed new app versions to Google Play and the App Store.
Lead Full-stack Developer
AlertCache
- Set up DevOps tools and services for agile development.
- Built a website that helps people save time by simplifying how they manage alerts from various sources.
- Developed a back-end API with Laravel and MongoDB.
- Created landing pages using Squarespace and a web app front end with Vue, Vuex, and BootstrapVue.
- Invented an email text parsing algorithm to parse notification or alert emails from various sources and implemented it with PHP.
- Implemented a custom email relaying service using SendGrid's Inbound Parse service.
- Implemented a custom ticket management service using ConnectWise Manage API.
- Integrated a Magnus Box API to manage alerts from Magnus Box in the Alert Cache dashboard.
- Collected tens of thousands of email notifications, cleaned the data, annotated them with appropriate labels, and performed feature engineering on the collected data.
- Built a hybrid model that consists of Random Forest and bags-of-words deep learning model, trained it, and deployed it for internal use.
Senior Front-end Developer
Broadlume
- Developed a website to introduce the flooring industry and announce conferences on flooring technology.
- Revised and updated the UI/UX design based on development needs.
- Implemented the UI/UX design using React, Gatsby, and Bootstrap.
- Tracked and fixed bugs and issues using GitHub as an issue tracking board.
Senior Full-stack Developer
Tiny Talk
- Developed a social app that allows random one-to-one or group video chats that last seven minutes.
- Implemented a server-less back-end solution using Firebase Authentication, Cloud Firestore, Firebase Cloud Storage, Firebase Cloud Functions, and Firebase Cloud Messaging (FCM) services.
- Built a mobile app and implemented a complicated UI/UX design using Flutter.
- Implemented one-to-one and group video calls on the app using Agora RTC Engine.
- Implemented deep linking to channels and video calls using Firebase Dynamic Links.
Lead Full-stack Developer
Aficionado, Inc.
- Developed a free music radio app that allows users to create their radio stations, connect with other music lovers, promote their music and shows, and broadcast music news.
- Developed a back-end API with Node.js, GraphQL, Apollo Server, and MySQL.
- Integrated a MediaNet Open API to implement a search function to look up songs, artists, and albums.
- Used Jira as a reporting and issue management tool to track and fix bugs and issues,.
- Developed a mobile app and implemented a beautiful UI/UX design with React Native, Redux, and Apollo Client.
Lead Full-stack Developer
Kiskoo
- Developed a sports polling website (betpolls.com) that provides users with the betting odds on each game and a user-friendly voting system, and supports fantasy sports games.
- Developed a back-end API using PHP, Lumen, and MySQL.
- Created a web admin portal with React, Redux, and Shopify Polaris and a front-end portal with Laravel Blade templates and Bootstrap.
- Implemented various search engine optimization techniques using Google Tag Manager and Ahrefs as SEO tools.
Senior Mobile App Developer
Kiskoo
- Developed several mobile apps to show instant results of all lotteries played in the United States and Latin America, especially in the Dominican Republic. More than 500,000 users use them.
- Integrated an API for Conectate Sports to get lottery data.
- Developed mobile apps and implemented complicated UI and UX with React Native, Redux, and Redux Thunk.
- Implemented banner, reward, and interstitial ads using Google AdMob.
Senior Full-stack Developer
Kiskoo
- Developed a website to satisfy the needs of different sectors of the Dominican market, including the movie, music, technology, automotive, sports, tourism, fashion, and other industries.
- Tracked and fixed bugs and issues using Jira as a reporting tool.
- Developed several subdomains using WordPress, Laravel, CakePHP, React, HTML, CSS, JavaScript, and Bootstrap.
- Implemented search engine optimization using Google Tag Manager and Ahrefs.
- Implemented banner, interstitial, and reward ads using Google Ads.
Experience
Free Music Player Radio App | Vybn
My other responsibilities included:
- Getting business ideas and graphic designs from the CEO and updating them according to technical needs.
- Building and updating React Native app components for new features.
- Building a back-end API with Node.js and Apollo Server to implement features.
- Deploying the back-end API updates to the API hosting server.
- Deploying new app versions to Google Play and App Store.
- Assigning specific tasks to junior developers, checking their work, and managing them.
Tiny Talk Chat
https://tinytalk.io/I built a server-less back-end solution using Firebase services and a mobile app with Flutter and various Flutter packages, including Agora RTC Engine.
My other responsibilities included:
- Getting the business ideas and graphic designs from the CEO and updating them according to technical needs.
- Building Flutter app components and logic to implement new features.
- Creating Firebase Firestore collections and security rules.
- Writing Firebase Functions for the back-end triggers and complex Firestore queries.
- Building and deploying new app versions to Google Play and App Store.
Alert Cache
https://alertcache.com/My other responsibilities included:
- Getting the business ideas from the CEO and converting them to wireframe and visual designs.
- Coming up with email alert parsing algorithms and implementing them with Laravel and PHP.
- Building the back-end API with Laravel and MongoDB and the web front end with Vue and BootstrapVue.
- Integrating third-party libraries, including ConnectWise, Magnus Box, etc.
- Managing the domain and the hosting server.
- Assigning specific tasks to junior developers, checking their work, and deploying updates to the server.
Hive Social
https://apps.apple.com/us/app/hive-social/id1480835284Broadlume
https://broadlume.comConectate
https://conectate.com.doMillions of users currently use the website. It consists of many sub-projects. As a full-stack developer, I built and updated the main site and several sub-sites using various technologies, including WordPress, Laravel, Lumen, React, MySQL, etc. The most important tasks were SEO and mobile responsiveness.
Education
Bachelor's Degree in Computer Science
Dalian University of Technology - Dalian, Liaoning, China
Certifications
Android Jetpack Masterclass in Kotlin
Udemy
Skills
Libraries/APIs
Vue.js, SendGrid API, React.js, Node.js, JavaScript, Stripe Development, REST API, Django, Web3.js, Stripe Development, TensorFlow, Twilio Development, Twilio Sync API, Nylas API, Recharts, React.js, Google Maps Development, Socket.IO, iOS, Gmail API, Google Calendar API, Sockets, Pandas, Protobuf, Keras, MusicKit
Tools
GitHub, Bitbucket, Git, Agora, Firebase Authentication, Firebase Cloud Messaging (FCM), React Apollo, Ahrefs, Redux Thunk, Sequelize, Apache, Webpack, WebView, Git, Crashlytics, Jira, Create React App, Android, Gradle, Xcode, React.js, Babel, JavaScript, Mocha, Expo, Nginx, Amazon Simple Queue Service (SQS), ChatGPT, Celery, Trello Development, Mongoose, Atlassian, Prisma, Terraform, Figma, Auth0, React Native, SendGrid, Vultr, Cron, Firebase Analytics, Android Jetpack
Languages
C#, Java, HTML, CSS, JavaScript, Python, PHP, Dart, GraphQL, Go, SCSS, Swift, Kotlin, SQL, TypeScript, Solidity, HTML5, C++, Rust, Python, Objective-C, CSS3, .NET, C, JavaScript, ECMAScript (ES6), Sass, Less
Frameworks
Laravel, Flutter, React Native, Lumen, Redux, Bootstrap, Django, Angular, AngularJS, Express.js, Tailwind CSS, .NET, Next.js, Django, ASP.NET, Android SDK, Material UI, .NET Core, SwiftUI, JSON Web Tokens (JWT), Swift, Cypress, Vuetify, OAuth, ASP.NET, Blazor, iOS, Qt Development, Ruby on Rails, CakePHP, Jest, gRPC, NestJS, Flask, tRPC
Paradigms
SEO, Automated Testing, Testing, MEAN Stack, DevOps, Agile Development, Web Development, Cross-Platform, API, Object-oriented Programming (OOP), Responsive Web Design, REST, Microservices Development, Unit Testing, Object-relational Mapping (ORM), Mobile App Design
Platforms
Android, MacOS, Firebase, Cloud Engineering, WordPress Development, Google Ads, Amazon EC2, Mobile App Design, Blockchain, iOS, Linux, AWS, Ethereum, LAMP, Web Development, AWS Elastic Beanstalk, Docker, AWS Lambda, Kubernetes, DigitalOcean, Vercel, Twilio Development, Heroku, Mapbox, Azure, Netlify
Storage
MongoDB, Firestore, MySQL, Amazon S3, PostgreSQL, Database, JSON, Google Cloud Development, NoSQL, Database Administration (DBA), AWS, Realm, SQL Server, Elasticsearch
Industry Expertise
Social Media Marketing
Other
Algorithms, Optimization, Software QA, Firebase Cloud Functions, Firebase Dynamic Links, Apollo Server, Shopify Polaris, AdMob, Google Tag Manager, WebSockets, AWS RDS, Crypto, Full-stack, UI Development, UX Development, APIs, NFT, Smart Contract Development, E-commerce marketing, Startup Development, Social Media Apps, Front-end, Finance, Back-end Developers, Apollo, API Integration, CI/CD Pipelines, Mobile Apps, Cross-platform App Development, Mobile App Design, Storage, In-app Purchases, In-app Messaging Systems, Analytics Development, Deep Linking, Jira Administration, Jira Administration, Mobile Architecture, Web Development, Data Engineering, Data Science, Mobile App Design, App Store Development, Google Play Store, App Store Acceptance Process, Web Scraping, Blade Templates, Monorepos, Lambda Functions, Minimum Viable Product (MVP), Social Media Platforms, Web3, Data Scraping, Web Development, Artificial Intelligence, Cloud Engineering, Full-stack, Machine Learning, Ajax, QA Testing, Sports & Athletics, Mobile First, Cloud Platforms, Maps, Documentation, Mobile App Design, Live Chat, Front-end Development, ERC-20, Data Structures, Video Streaming, Charts, Instant Messaging, Containerization, Responsive Web Development, Web Development, Site Reliability, CSV, Audio, Videos, Data Visualization, Mathematics, Graphs, Quantitative Analysis, Trading, SEO Tools, GPT-4, Storybook, Software Architecture, Scalability, Responsive Design, Cross-browser Compatibility, CRM, Serverless, OpenAI GPT-3 API, Architecture, MERN Stack, New Product Development, Applications, Software Integration, WordPress Multi-user, Music, Audio Streaming, Chatbot Development, Google SEO, Cloudinary, Async/Await, GitHub Workflows, SEO, Payment APIs, Back-end Developers, Distributed Systems, Generative Pre-trained Transformers (GPT), GPT-3, Analytical Dashboards, Software Development, Leadership, Web Components, Client Relationship Management, Integration, Decentralized Finance (DeFi), Data Science, Infrastructure as Code (IaC), AWS Cloud, FastAPI, Game Development, Data Analysis, Asynchronous I/O, Cryptocurrency, ConnectWise, GatsbyJS, Fintech Development, Automated Build System, Embedded Systems Engineering, Geolocation, Solana, Vue Router, DNS, SDKs, Deep Learning, Random Forests
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