Chris Liang, Developer in Vladivostok, Primorsky Krai, Russia
Chris is available for hire
Hire Chris

Chris Liang

Verified Expert  in Engineering

Software Developer

Location
Vladivostok, Primorsky Krai, Russia
Toptal Member Since
October 1, 2016

Chris loves creating web apps and iOS/Android apps. Over the past decade, he's developed more than 100 apps—providing a comprehensive UI/UX in geolocation service, real-time messaging, and other social features. He specializes in developing desktop and mobile apps related to real estate and food industries. Chris is an open-minded and personable developer who loves working with other developers in a team environment.

iPadData MiningApolloMySQLJavaScriptCSSMacOSXcodeAgile Software DevelopmentAgileModel View Controller (MVC)iOSCocoaPodsCocoaObjective-CiBeaconYelp APIBasecampGeolocationAsana

Portfolio

Everfit, Inc. (via Toptal)
React Native, GraphQL, Apollo, React
Enroute 911
Google Maps, Mapbox, Redux-Saga, React Native
NZXT
Android, Swift, React Native

Experience

HTML - 10 yearsRuby on Rails (RoR) - 7 yearsSwift - 5 yearsReact - 5 yearsNode.js - 5 yearsReact Native - 4 yearsReact Redux - 4 yearsVue - 4 years

Availability

Part-time

Preferred Environment

Visual Studio Code (VS Code), Android Studio, Xcode

The most amazing...

...thing I've built was a fitness coach management system in React (Apollo GraphQL) along with a React Native mobile app.

Work Experience

Senior Full-stack Developer

2019 - 2019
Everfit, Inc. (via Toptal)
  • Built a dashboard to manage coaches (CRUD operation) with React (Apollo GraphQL) and iOS & Android mobile apps in React Native that are used by clients.
  • Wrote customized webhooks for Twilio messaging between clients and coaches.
  • Developed cron jobs to send notifications to coaches based on the SMSes received from the clients.
  • Built a survey system for both web app and mobile app.
  • Wrote migrations and seeding with Knex.
  • Used the Serverless framework.
Technologies: React Native, GraphQL, Apollo, React

Senior Front-end Developer

2018 - 2019
Enroute 911
  • Improved code quality by converting old JavaScript code to ES7 and via modularization.
  • Reduced initial loading time by 300% by finding and fixing the logical errors in the code.
  • Integrated Google Maps, MapBox, and several other map SDKs.
  • Introduced Redux-saga to keep calling the RESTful APIs in the background.
Technologies: Google Maps, Mapbox, Redux-Saga, React Native

Senior Mobile Developer

2018 - 2018
NZXT
  • Developed a mobile app to get and update the PC status while playing games.
  • Utilized BLE technology to get and connect with devices near a mobile phone.
  • Called RESTful APIs for devices far away and used socket connection for devices near mobile phone to get the realtime data of the PC.
  • Used GCD multithreading to call several APIs at once.
  • Implemented Redux-saga to keep calling RESTful APIs in the background.
Technologies: Android, Swift, React Native

Senior Full-stack Developer

2017 - 2018
Flexible Fitness, LLC
  • Updated non-structured code to MVC architecture.
  • Integrated Apple HealthKit and Google Fit for retrieving user health information such as the number of steps and weight.
  • Integrated Apple Pay and Google Pay for in-app purchase function.
  • Integrated OneSignal for push notification.
  • Developed the front end in React.js(Redux Saga) and the back end in Node.js (ExpressJS).
  • Implemented Sketch design to pure HTML/CSS.
  • Used Bluetooth Beacon to connect with fitness devices.
Technologies: Redux-Saga, Express.js, Node.js, React Native

iOS Developer

2016 - 2016
MeeCard
  • Implemented BaaS using Parse.
  • Developed an offline mode using local storage.
  • Helped to develop the business requirements.
  • Developed a push notification using APNs.
Technologies: Git, Objective-C

iOS Developer

2016 - 2016
Textgreets
  • Developed real-time messaging using QuickBlox.
  • Implemented geofencing using Google Maps SDK and Core Location.
  • Integrated an in-app payment using Stripe, ApplePay, and PayPal.
  • Created UI animations using Core Animation.
  • Developed an offline mode using CoreData and Realm.
  • Made push notification using OneSignal.
  • Developed unit testing and UI testing.
Technologies: JavaScript, Objective-C, Git, Swift

Senior iOS Developer

2014 - 2016
TextUs Biz
  • Provided the business logic needed for point of sales.
  • Developed an offline mode using Core Data.
  • Created a payment integration using Braintree.
  • Enabled a credit card validation feature using Card.io.
  • Implemented Apple Pay.
  • Used WatchKit and OpenGL.
Technologies: Git, Swift, .NET, Objective-C

iOS Developer

2013 - 2016
RapidSOS
  • Built a location-based service using Core Location and Google Maps SDK.
  • Created a push notification-based messaging service.
  • Developed VoIP call using PJSIP library.
  • Created UI and unit testing using XCTest.
  • Developed an offline mode using Core Data.
Technologies: Git, JavaScript, Swift, Objective-C, iOS

iOS Developer

2015 - 2015
AppleSolutions DK
  • Implemented a Shopify Client SDK and a Google Maps SDK.
  • Added Apple WatchKit.
  • Created a beacon using Estimote SDK.
  • Added a payment integration using Apple Pay.
  • Implemented a 3D touch feature.
Technologies: Git, Objective-C

iOS Developer

2014 - 2014
Beero
  • Created rich animations using UIkit and Core Animation.
  • Developed an offline mode.
  • Enabled geofencing using Core Location and Google Maps SDK.
  • Implemented a payment integration using PayPal.
Technologies: Git, iOS, Objective-C

TXG Mock Data Manager

A manager class designed to manage mock data. This class was necessary because the back-end infrastructure was not yet available, and it was required to make the application functional for a presentation.

To simulate the back-end functionality, the manager class loads PLIST files from an app bundle and utilizes them. It should be noted that this manager class is intended to be replaced by actual managers that communicate with the back end once it becomes available.

Beero iOS App

• Created rich animations using UIkit and Core Animation. • Developed an offline mode.
• Enabled geofencing using Core Location and Google Maps SDK.
• Implemented a payment integration using PayPal.

AppleSolutions

• Implemented a Shopify Client SDK and a Google Maps SDK.
• Added Apple WatchKit.
• Created a beacon using Estimote SDK.
• Added a payment integration using Apple Pay.
• Implemented a 3D touch feature.

RapidSOS iOS and Android

• Built a location-based service using Core Location and Google Maps SDK.
• Created a push notification-based messaging service.
• Developed VoIP call using PJSIP library.
• Created UI and unit testing using XCTest.
• Developed an offline mode using Core Data.

TextUs Biz

• Provided the business logic needed for point of sales.
• Developed an offline mode using Core Data.
• Created a payment integration using Braintree.
• Enabled a credit card validation feature using Card.io.
• Implemented Apple Pay.
• Used WatchKit and OpenGL.

Textgreets

• Developed real-time messaging using QuickBlox.
• Implemented geofencing using Google Maps SDK and Core Location.
• Integrated an in-app payment using Stripe, ApplePay, and PayPal.
• Created UI animations using Core Animation.
• Developed an offline mode using CoreData and Realm.
• Implemented push notification using OneSignal.
• Developed unit testing and UI testing.

MeeCard

• Used Parse for the back end.
• Developed an offline mode using local storage.
• Helped to develop the business requirements.
• Developed push notifications using APNs.

Flexible Fitness React Native App

• Updated the non-structured code base to MVC architecture
• Integrated HealthKit and GoogleFit for getting user details such as number of steps, weight, blood pressure, etc.
• Integrated Apple Pay and Google Pay for in app purchase feature
• Pixel perfect implementation of the new UI given by the client
• Used React.js(Redux-saga) for front end, Pure Javacript(ES5), and Node.js(ExpressJS) for backend
• Implemented Sketch design to pure HTML/CSS

KudosFit (via Toptal)

https://www.kudos.fit/
The purpose of this project was to provide real-time coaching to clients via a mobile app helmed by actual coaches.

Role: Senior Full-stack Developer

I built both desktop web app and mobile app in React (Apollo GraphQL) and React Native.

This project used Apollo GraphQL with a serverless framework for the desktop app. It was already on air and I needed to write a lot of migration scripts and seeding every time, I wrote a new function or add a new feature based on Knex.

I also built a dashboard to manage the coaches' apps (CRUD operation) and clients' iOS & Android mobile apps. I also wrote customized webhooks for Twilio messaging between clients and coaches and cron jobs to send notifications to coaches based on the SMSs received from the clients.

I was able to fix several bugs and add more than five new features of the app in less than two months.

Languages

PHP, JavaScript, Swift, Objective-C, GraphQL, HTML, CSS, SCSS, TypeScript, C++, C, Java

Frameworks

Core Bluetooth, Cocoa, React Native, Angular, Express.js, Bootstrap, RealmSwift, MapKit, Serverless Framework, Laravel, Ruby on Rails (RoR), .NET

Libraries/APIs

CocoaPods, Node.js, React, Facebook Login, Parse SDK, Plaid API, Instagram API, Google Places API, Google Maps SDK, Google Geocoding API, Yelp API, Foursquare API, Mapbox iOS SDK, Braintree API, React Redux, Vue, Twilio API, Redux-Saga, Google Maps

Tools

Xcode, Android Studio, Jira, Trello, Asana, Basecamp, OneSignal, React Apollo, Knex.js, MongoLab, Git

Paradigms

Model View ViewModel (MVVM), MVC Design, Agile Software Development, Agile, Model View Controller (MVC), Continuous Deployment, Continuous Integration (CI), Scrum

Platforms

MacOS, iOS, Amazon EC2, Firebase, Visual Studio Code (VS Code), iOS 12, Twilio, Oracle, Linux, WordPress, Android, Bluetooth LE, Mapbox

Storage

MSSQLCE, MySQL, Amazon S3 (AWS S3), Elasticsearch, MongoDB, Realm, MySQLdb, SQLite

Other

Web Development, iPhone, iPad, Google Login, Stripe Payments, Geolocation, Data Mining, Apollo, iBeacon, Serverless, Bluetooth Beacons, Development

2007 - 2009

Master's Degree in Computer Engineering

Far Eastern Federal University - Vladivostok, Russia

2003 - 2007

Bachelor's Degree in Computer Engineering

Far Eastern Federal University - Vladivostok, Russia

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring