Kerwin is available for hire

Kerwin Anthony J. Tang

Verified Expert in Engineering

Full-stack Developer

Location

Manila, NCR, Philippines

Toptal Member Since

September 30, 2017

Kerwin is an experienced full-stack developer, with 14 years of solid experience in web and mobile application development using the latest technologies. He also has extensive experience leading software development teams, project management, systems architecture, and salesforce.com.

Web Development Front-end Full-stack Algorithms Analytics Back-end Data Visualization MySQL JavaScript CSS HTML5 SQL Linux Java Oracle 11g ColdFusion

Portfolio

Kalepa

React, Python, TypeScript, CSS, Next.js, Amazon Web Services (AWS), SQL, Jest...

SMRI

Node.js, MongoDB, GraphQL, React Native, React, CSS, Amazon Web Services (AWS)...

Poliscore

React Native, SQL, HTML, Front-end, APIs, Agile, JavaScript, Web Applications...

Experience

JavaScript - 20 years Java - 14 years Grails - 8 years React - 7 years Node.js - 5 years Salesforce - 4 years React Native - 3 years Omnichannel Marketing - 2 years

Availability

Part-time

Preferred Environment

Xcode, Visual Studio Code (VS Code), MacOS

The most amazing...

...project I've worked on is a cloud-based medical records mobile app built on React Native and NodeJS. I did it all in 4 weeks!

Work Experience

Front-end Engineer

2019 - PRESENT

Kalepa

Developed Kalepa Copilot application. Built the front-end application with React.
Engineered web crawlers that ingest data from different sources.
Served as the technical lead in the development of the Copilot web application.

Technologies: React, Python, TypeScript, CSS, Next.js, Amazon Web Services (AWS), SQL, Jest, HTML5, HTML, Front-end, APIs, Agile, JavaScript, Data Visualization, Web Applications, API Development, Full-stack, Front-end Development, User Experience (UX), Material UI, SaaS, Git, MySQL, Architecture, Technical Leadership, Figma, Jira, User Interface (UI), PostgreSQL, Docker, Algorithms, Web Development, Firebase, Back-end, MUI CSS, Responsive Web Apps, REST APIs, GitHub, Auth0, Postman

Senior Manager | Lead Developer

2017 - PRESENT

SMRI

Built three mobile apps for an eCommerce and product catalog using React Native.
Created a gift registry site using React and Node.js.
Developed a marketing web application using React.
Built a back-end job for creating reports and sales invoices.
Pioneered an omnichannel platform for the company, anticipating millions of users.

Technologies: Node.js, MongoDB, GraphQL, React Native, React, CSS, Amazon Web Services (AWS), Express.js, SQL, HTML5, HTML, Front-end, APIs, Agile, JavaScript, Data Visualization, Web Applications, API Development, Team Leadership, Key Performance Indicators (KPIs), eCommerce, Full-stack, Front-end Development, User Experience (UX), Material UI, Git, MySQL, Architecture, Mobile Development, Project Management, Technical Leadership, Jira, User Interface (UI), PostgreSQL, Algorithms, Web Development, Back-end, Responsive Web Apps, REST APIs, GitHub, Postman

React Native Developer

2018 - 2018

Poliscore

Built a mobile app prototype based on screen designs and wireframes.

Technologies: React Native, SQL, HTML, Front-end, APIs, Agile, JavaScript, Web Applications, API Development, Full-stack, Front-end Development, User Experience (UX), Git, Architecture, Mobile Development, User Interface (UI), Algorithms, Back-end, REST APIs, GitHub, Postman

Full-stack Engineer

2018 - 2018

Replenysh (via Toptal)

Built a mobile app with QR Code scanning capability using React Native.
Worked with SMS notifications to multiple users using Front App.
Helped create new features for the company's main website using React, NodeJS, and ElmJS.

Technologies: Elm, Node.js, React Native, React, CSS, SQL, HTML5, HTML, Front-end, APIs, Agile, JavaScript, Web Applications, API Development, Full-stack, Front-end Development, User Experience (UX), Git, User Interface (UI), Algorithms, Web Development, REST APIs, GitHub, Postman

Lead Software Developer | Senior Manager

2016 - 2017

MBTC

Developed the bank's mobile banking application built on Cordova, AngularJS, and a Jakarta EE back end. Integrated with third-party services like Google Places and telecom services.
Built an in-house rewards application system using Groovy on Grails and MySQL, integrating with Active Directory.
Created an interactive employee portal built on Meteor and MongoDB.
Managed a small development team of full-stack developers that created small POC applications.
Contributed to the architectural design of the omnichannel platform built on microservices architecture based on a cloud infrastructure.

Technologies: Grails, Groovy, Cordova, Objective-C, Node.js, Java, JavaScript, Amazon Web Services (AWS), SQL, HTML5, HTML, Front-end, APIs, Agile, Data Visualization, Web Applications, API Development, Team Leadership, Key Performance Indicators (KPIs), Fintech, Full-stack, Front-end Development, User Experience (UX), Material UI, Git, MySQL, jQuery, Architecture, Mobile Development, Project Management, Technical Leadership, Jira, User Interface (UI), Algorithms, Web Development, Back-end, Responsive Web Apps, REST APIs, GitHub, Postman

Director of I.T.

2008 - 2016

JWay Group, Inc.

Developed multiple projects across domains including, but not limited to, supply chain, inventory, remittance, multi-level marketing, manufacturing, warehouse, medical industry, games, social media, etc.
Built a large-scale web and mobile application to help one of our global supply chain clients, using iOS, Android, and Ruby on Rails.
Contributed to the development of a remittance application that integrates with the largest banks in the Philippines, built on Groovy on Grails and a MySQL database.
Led a software development team of 20 developers that built multiple web and mobile application solutions.
Built in-house applications for enterprise clients like Sun Microsystems, Visa, etc., using Salesforce.com solutions.
Certified as a Salesforce.com developer for six years.

Technologies: Android, Objective-C, JavaScript, Grails, Groovy, Ruby on Rails (RoR), Ruby, CSS, Amazon Web Services (AWS), SQL, HTML5, HTML, Front-end, APIs, Agile, Data Visualization, Web Applications, API Development, Team Leadership, Key Performance Indicators (KPIs), Full-stack, Front-end Development, User Experience (UX), Bitbucket, SaaS, Git, MySQL, jQuery, Architecture, Mobile Development, Project Management, CTO, Technical Leadership, Jira, User Interface (UI), PostgreSQL, Algorithms, Web Development, Google Analytics, WordPress, HIPAA Compliance, Back-end, Responsive Web Apps, REST APIs, GitHub, Postman

Senior Software Developer

2004 - 2008

Azeus Systems Philippines Inc.

Developed multiple web application projects for HK government using a Java-based in-house MVC framework.
Built an in-house time-tracking tool using VB.Net.
Performed HTML/CSS/Javascript training for new developers.
Performed Technical Lead roles on major projects including code reviews, mentorships, and code improvements on our big projects.
Implemented Performance Tuning on enterprise applications which include performance enhancement on SQL queries accessing millions of records; code improvements on sub-optimal blocks of code; and the use of stress test tools like LoadUI and Microsoft Web Application Stress Tool.

Technologies: CSS, HTML, JavaScript, Java, SQL, Front-end, Web Applications, Full-stack, Front-end Development, User Experience (UX), MySQL, jQuery, User Interface (UI), Algorithms, Web Development

Experience

Ace Hardware Philippines App (iOS/Android)

Built a catalog mobile application for Ace Hardware in the Philippines, using React Native for the front-end and nodeJS + graphQL on the back-end.

Replenysh (iOS/Android)

https://www.replenysh.com

Built a mobile app for recyclables pickup and delivery, and it includes monitoring of delivery statuses and tracking via the app.

Appliance Center Catalog (iOS/Android)

https://www.smappliance.com/

Built a catalog mobile application for appliances from the biggest retailer in the Philippines, using React Native for the front-end and nodeJS + graphQL.

App is used internally in-store, so it is not publicly available via app store/play store. However, the web version is publicly available.

Poliscore App (iOS/Android)

Built an MVP for a socio-political app relating to government bills and how they relate to user's point of view. Used React Native framework.

Home Product Catalog App (iOS/Android)

Built an app for a product catalog for a home and furniture retail company. This app is internal use only.

Knock Knock App

http://fb.com/knockknock.mobileapp

Knock Knock App is a simple fun game where users can collect items based on different locations in the city. It involves knocking on a door and if you're at the right place, Bella (the main character) will open the door and give you an item to collect.

Medi-Q

Medi-Q is a mobile application for cloud-based electronic medical records. Its main purpose is to connect patients and doctors through the application.

Smart appointments, queueing, and patient profiles are all available on the app, anytime, anywhere.

Skills

Languages

HTML, CSS, Java, JavaScript, SQL, HTML5, PHP, Objective-C, Groovy, TypeScript, GraphQL, Ruby, Elm, Python

Frameworks

React Native, Grails, Android SDK, Redux, Express.js, Next.js, Jest, Material UI, MUI CSS, Ruby on Rails (RoR)

Libraries/APIs

React, Node.js, API Development, jQuery, REST APIs, Chai, React Redux

Tools

Git, GitHub, Android Studio, Xcode, Mocha, Adobe ColdFusion, React Apollo, Jira, Auth0, Postman, Bitbucket, Figma, Google Analytics

Paradigms

UX Design, Object-oriented Programming (OOP), Agile, Agile Software Development, Mobile Development, HIPAA Compliance

Platforms

MacOS, Linux, iOS, Salesforce, Visual Studio Code (VS Code), Jakarta EE, Amazon Web Services (AWS), WordPress, Android, Docker, Firebase

Storage

PostgreSQL, MySQL, Oracle 11g, MongoDB

Industry Expertise

Project Management

Other

Product Design, Analytics, Performance Optimization, Front-end, APIs, Data Visualization, Web Applications, Team Leadership, Full-stack, Front-end Development, Architecture, Technical Leadership, Algorithms, Web Development, Back-end, Responsive Web Apps, Innovation, Omnichannel Marketing, Salesforce Apex, Salesforce.com Developer Certification, Key Performance Indicators (KPIs), eCommerce, Fintech, User Experience (UX), SaaS, CTO, User Interface (UI), Cordova

Education

1999 - 2003

Bachelor of Science Degree in Computer Science

University of the Philippines - Diliman, Quezon City, Philippines

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.

Share your needs

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

Choose your talent

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

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