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JinGang Liu

JinGang Liu

Dandong, Liaoning, China
Member since July 24, 2015
JinGang is a professional web and mobile developer with extensive experience developing enterprise software. He also has freelancing experience delivering social, taxi, real estate, and fitness apps, among others. He works with a diverse range of technologies like PHP, Node.js, or Python, and he prides himself on his sophisticated, reusable, and customizable code. He focuses on maintainability and accessibility in all of his products.
JinGang is now available for hire
  • SQL, 15 years
  • Python, 9 years
  • PHP, 9 years
  • Django, 8 years
  • iOS, 7 years
  • Node.js, 6 years
  • Android, 6 years
  • React, 4 years
Dandong, Liaoning, China
Preferred Environment
Xcode, Sublime Text, WebStorm, Android Studio
The most amazing... I've developed is a taxi service app used widely in China.
  • Web Developer
    2018 - 2018
    Drive Social
    • Provided full-stack web development for an existing platform.
    • Integrated with Facebook marketing API endpoints using PHP.
    • Implemented Facebook user authentication for a Facebook marketing API endpoint.
    • Migrated the old codebase using Redux.
    • Refined the codebase conforming to new standards.
    Technologies: PHP, PostgreSQL, Laravel, JavaScript, React, Redux, HTML5, CSS3
  • Full-stack Web Developer
    2018 - 2018
    Qomm, Pte., Ltd. (via Toptal)
    • Developed back-end API endpoints to consume data and maintain the status of a chat SPA.
    • Integrated with an XMPP back-end service to implement chat functions.
    • Worked on server deployment and DevOps engineering using Google Cloud Platform.
    • Integrated with GCP services like Google Storage.
    • Worked on the front-end side using React and Redux.
    Technologies: Ruby on Rails, JavaScript, TypeScript, React, Redux, Web Sockets, XMPP, HTML5, CSS3
  • Full-stack Developer
    2018 - 2018
    Geopier West (via Toptal)
    • Replicated an existing internal iOS app and its back-end service.
    • Integrated Excel files on the back-end side, as the app was primarily used for data management.
    • Covered almost 80% of my codebase under unit testing.
    • Wrote a reusable, testable, and clean codebase for readability and maintainability.
    • Worked on back-end service deployment using AWS EBS.
    Technologies: Python, Django, PostgreSQL, Django REST Framework, React Native, iOS, JavaScript, HTML5, CSS3
  • Freelance Senior Back-end Developer
    2017 - 2017
    BrokerGenius, Inc. (via Toptal)
    • Worked on a highly scalable, performance-critical web service which requires a clean, testable, and reliable codebase.
    • Worked in the agile team environment with the back-end team of developers in Barcelona.
    • Integrated with third-party services like Stubhub and VividSeats.
    • Collaborated closely with the QA team and participated in various kind of testings and demos.
    • Worked on special algorithms and methodologies to improve the performance.
    Technologies: PHP, Laravel, MySQL, Redis, REST, SQL Server
  • Freelance iOS Developer
    2016 - 2016
    iDialogs (via Toptal)
    • Worked as a Swift developer for the iDialogs team.
    • Collaborated with other developers and clients (who provided new requirements) in the DevOps team.
    • Developed the Today widget for the app.
    • Converted XLForm codes to use Eureka.
    • Developed other modules and provided ongoing support and upgrades.
    Technologies: Swift 2, Swift 3, Alamofire, Core Data, SQLite, HealthKit, Eureka, XLForm
  • Freelance Lead Developer
    2016 - 2016
    PhysioHealth (via Toptal)
    • Led development, providing guidance to iOS and Android developers.
    • Developed the back-end and implemented new features such as connecting to Fitbit, Jawbone, Google Fit, and HealthKit systems.
    • Supported the live product and fixed server errors.
    Technologies: Node.js, Express.js, MongoDB, AWS EC2, AWS S3, SSL, Logentries, Swift, Objective-C
  • Freelance iOS Developer
    2015 - 2016
    Precoa (via Toptal)
    • Developed the Legacy Video app.
    • Created an AWS S3 bucket for uploading videos.
    • Tested a RESTful API.
    Technologies: Objective-C, AVFoundation, GPUImage, AFNetworking, AWS S3
  • Full-stack Mobile Developer
    2014 - 2015
    • Developed social, taxi, real estate, fitness, and other apps for a variety of clients.
    Technologies: Objective-C, Java, PHP, Laravel, Parse, AWS, GoDaddy
  • Project Manger for Mobile Apps
    2011 - 2014
    Intechno China
    • Led a photo and story sharing app project. This project demonstrated the company's competency for its cost-effective, future-oriented, and quality-centered approach.
    • Oversaw a navigation assistant app project (iOS/Android) which utilized multiple map services (similar to Waze).
    • Managed a contest app project in collaboration with CCTV.
    • Led a real estate app project with eCommerce feature.
    • Oversaw the creation of an integrated warehouse management system which let warehouse workers record the status of barcode scanning devices like Honeywell barcode scanners.
    • Managed the creation of mobile apps which are used in distributed working environment to track the location and status of workers.
    Technologies: iOS (iPhone+iPad), Android
  • Mobile Developer (iOS, Android)
    2009 - 2011
    Intechno China
    • Developed social networking iOS apps which have posting, sharing, and chatting features. I also utilized technologies like Bluetooth LE for finding people.
    • Wrote "Coding Guidelines for Maintenance, Reusability and Scalability," a guide for Intechno mobile app developers.
    • Developed taxi apps with GPS and Map integration, which utilizes Google Maps, Baidu Map, and Apple Maps. The taxi apps had social features in addition to default features like scheduling and match making.
    • Developed eCommerce apps, using payment gateways such as PayPal.
    • Developed the back-end for some small/middle-scaled mobile app projects.
    • Developed real estate apps.
    Technologies: Objective-C, Java, Xcode, iOS, Android
  • Project Manager
    2005 - 2009
    • Led the upgrade of a bank website. The project covered adding new functions and improving the performance.
    • Oversaw the connection of distributed data servers for an enterprise.
    • Managed the customization of the template product for business organizations.
    • Supervised the development of new components for the template product. (CRM, Sales Management, Data Mining).
    • Spearheaded the improvement of the company product based on new requirements analyzed.
    Technologies: Zend, MySQL, Python, MongoDB, .NET
  • Team Leader
    2004 - 2005
    • Led a team to develop a bank website.
    • Set guidelines for quality assurance and quality control.
    • Architected procedures to estimate the development capacity of individual developers and teams.
    • Carried out code review and quality testing.
    • Interfaced with the customers to analyze requirements and accept feedback.
    Technologies: Zend, MySQL, PHP
  • Web Developer
    2002 - 2004
    • Contributed to the development of a website for a Chinese bank. Analyzed business logic and developed the web back-end.
    • Developed a customer management website template and customized it for several clients.
    • Optimized databases and back-end engines of already-existing products and carried out load testing.
    • Reviewed codes against proposed coding practices of the company.
    • Developed a shopping website with Zend and MySQL.
    Technologies: PHP, Zend, .NET, Java, Ruby, Python
  • Taxi App (Development)

    I developed the front-end and back-end of this mobile app with scalability and extensibility. New functions can be added easily and the scale of the back-end server can be extended easily. Now, the app handles a large number of users well and provides an awesome user experience.

  • Integrated Warehouse Management System (Web and Mobile) (Development)

    This system is composed of a front-end mobile app (mounted by Honeywell barcode scanning device), RESTful web service APIs, and Database. This system lets warehouse workers automate the working process and thus saves a lot of time, effort, and cost.

    The admin web page lets the manager see the trend of activities within the company (per worker, per product category, per day, etc.). This utilizes technologies like D3.js and React.js.

  • "Coding Guidelines for Maintenance, Reusability and Scalability" (Other amazing things)

    This document is distributed within Intechno China. It gives guides for developing professional codes, which guarantees an efficient and quality development process.

  • Social Networking App (Development)

    A dating app which has the following features:
    - Photo sharing
    - Posting articles
    - Finding stories nearby
    - Social networking (making friends, chatting, making events)
    - Seeing the real-time location of friends on a map

  • Real Estate App (Development)

    This real estate app lets users search real estate locations with a distance limit and compare prices of the houses which have similar features. The app also works as a marketplace where the contracts are made and payments are processed.

  • Location Tracking App (Development)

    This app is used for workers who work in a distributed environment or are under risk. This app tracks the location of the worker and reports the location and status of the worker to the boss in real time. This app can work without wifi.

  • Legacy Suite (Development)

    An iPad app which records the stories of the elderly, used in an assisted living facility.

    Features: Predefined questions and categories, adding custom questions, recording video as an answer to a question, uploading video to server

    Tech stack: iOS, Swift, Objective-C

  • iDialogs (Development)

    I worked as Swift developer on the iDialogs team. By using iDialogs, the user can track their exercise, blood glucose, weight, food consumption, etc. The tracked data is analyzed by a bot named iDa to give the user tips and suggestions.

  • PhysioHealth (Development)

    Role: Lead Developer, Back-end Developer

    A fitness activity tracking app that tracks running distance, steps, calories burnt, water drinks, etc. The app is integrated with fitness APIs - Fitbit, Jawbone, Google Fit, Apple HealthKit, Strava, Swarm, Runkeeper, and Moves.

    Tech stack: Node.js, AngularJS, Ionic, Cordova, Objective-C, Swift, Java

  • BrokerGenius (Development)

    Role: Senior Back-end Developer

    An auto pricing platform to help brokers price their tickets competitively. The platform is integrated with third-party APIs and POSes like Stubhub andTicketUtils.

    Tech stack: PHP 7, Laravel, MySQL, SQL Server, Redis, REST

  • Languages
    PHP, Objective-C, SQL, Java, JavaScript, Swift 2, Swift 3, Python, Ruby, C#
  • Frameworks
    Laravel, Ruby on Rails (RoR), AngularJS, Express.js, Django, Angular, Zend Framework, PhoneGap, Cordova, ReactiveCocoa
  • Libraries/APIs
    Node.js, React, Facebook API, RxSwift, Vue.js, Vue.js 2
  • Tools
    Xcode, Android Studio, WebStorm, PyCharm, RubyMine
  • Paradigms
    MEAN Stack, Functional Programming, Model View Viewmodel (MVVM), Functional Reactive Programming
  • Platforms
    iOS, Android
  • Storage
    MySQL, MongoDB
  • Bachelor's Degree in Software Engineering
    1998 - 2002
    Tsinghua University - Beijing
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