Zack is available for hire

Zack Yang

Verified Expert in Engineering

Software Developer

Sydney, New South Wales, Australia

Toptal member since March 23, 2022

Expertise

Full-stack Front-end Back-end Scalability WebSockets CSS5 MacOS Ruby Ruby on Rails (RoR)SQL Redis Sidekiq Stripe Development

Bio

Zack is a full-stack engineer with 10 years of experience building and polishing products for startup companies, focused on fintech and eCommerce. He has a solid understanding of concise coding principles and best practices and is proficient with Node.js, Ruby, JavaScript, React, PostgreSQL, MongoDB, and CI/CD. Zack created an eCommerce app that reached the top three in the Apple Store Life category, led teams, and delivered a dynamically configurable discount and reward system.

Portfolio

SatQuote LLC

React, Next.js, Tailwind CSS, Front-end, Artificial Intelligence (AI), Python

The Brynson Group, LLC

Ruby on Rails (RoR), React, APIs, Tailwind CSS, PostgreSQL, Heroku

Forbes Media - Q.ai - Main

Ruby on Rails (RoR), React, Google Cloud Platform (GCP), Apache Kafka, RabbitMQ...

Experience

Ruby on Rails (RoR) - 10 years JavaScript - 7 years PostgreSQL - 6 years Node.js - 4 years React - 4 years Express.js - 4 years TypeScript - 3 years Next.js - 2 years

Availability

Part-time

Preferred Environment

Jira, Tailwind CSS, Unit Testing, MERN Stack, RSpec, Next.js, Front-end, Rails Engines, Prisma, Rust

The most amazing...

...high-speed eCommerce platform I've built was for a mobile phone manufacturing company where the number of orders generated per second exceeds 50,000.

Work Experience

Next.js Full-stack Developer

2024 - PRESENT

SatQuote LLC

Developed a React and Next.js application that can use AI to help the company employees complete specific jobs, like generating invoices, arranging events, estimating costs, etc.
Built React applications from scratch and designed the architecture based on the business target.
Implemented the internal communication system via Kafka.
Built the CD/CD pipeline with the DevOps engineer and Docker files for different sub-microservices.

Technologies: React, Next.js, Tailwind CSS, Front-end, Artificial Intelligence (AI), Python

Senior Full-stack Developer

2024 - 2024

The Brynson Group, LLC

Developed a system that can help property leasing companies analyze and manage their leasing ads.
Created a reporting system that can be based on geolocation to find all nearby properties that are highly similar to the target property.
Implemented 20+ different charts via React, which can help clients analyze local leasing marketing.
Implemented a comprehensive DDCA system, which can automatically sync the features from the third-party API.
Used GraphQL to implement APIs for the front end.

Technologies: Ruby on Rails (RoR), React, APIs, Tailwind CSS, PostgreSQL, Heroku

Senior Software Engineer

2022 - 2024

Forbes Media - Q.ai - Main

Served as a team lead, overseeing the back-end server's development.
Implemented the trading system, which can generate and process more than one million transactions daily.
Improved the availability and stability of services by optimizing data structures and algorithms, increasing the trading success rate from about 50% to 96%.
Completed the new dashboard design and code implementation and refactored the legacy code.
Designed and implemented the architecture of the automatic test program.
Managed and maintained the most important business services and daily business tasks.

Technologies: Ruby on Rails (RoR), React, Google Cloud Platform (GCP), Apache Kafka, RabbitMQ, APIs, Auth0, Google Cloud, Tailwind CSS, REST, CI/CD Pipelines, RESTful Services, Front-end, Rails Engines, Serverless, Front-end Development, ECMAScript (ES6), API Development, API Integration

Software Engineer

2020 - 2021

Myfoodlink

Developed a service that automatically obtains product details through barcodes or product descriptions. It means that retailers do not need to enter detailed product information themselves.
Implemented the API service that automatically binds product images and product pages via OCR.
Implemented the store's template system, allowing customers to quickly deploy the website and list products through existing templates.

Technologies: Vue, Ruby on Rails (RoR), MongoDB, CSS, SEO Tools, APIs, Ubuntu, Redis, Software Testing, Software Analysis, Human-computer Interaction (HCI), HTML, HTML5, Back-end, CSS5, GraphQL, Mocha, Haml, GitHub, Git, Node.js, Amazon Web Services (AWS), TypeScript, WebSockets, Pub/Sub, Stripe, Full-stack, Unit Testing, Sideqik, MySQL, jQuery, Express.js, Sidekiq, Scalability, Amazon RDS, JavaScript, RSpec, REST APIs, Next.js, Docker, Jest, Cypress, REST, CI/CD Pipelines, RESTful Services, Front-end, Tailwind CSS, Rails Engines, Serverless, AWS Lambda, Sass, Front-end Development, ECMAScript (ES6), API Development, Elasticsearch, eCommerce, Google Maps SDK, API Integration

Full-stack Engineer

2017 - 2019

Sentia Australia

Implemented the development of a large-traffic data API and a single server that can process more than 10,000 real-time data per minute.
Participated in the development of a financing platform application for the Australian market. Completed multiple third-party services development for financial institutions.
Delivered a dynamically configurable discount and reward system for eCommerce platforms. Users can quickly create discount and point rules for products through the background DSL.

Technologies: JavaScript, Ruby on Rails (RoR), PostgreSQL, React, React Redux, Redis, Ubuntu, RSpec, Capybara, Jira, CSS, SEO Tools, APIs, New Relic, Software Testing, Software Analysis, HTML, HTML5, Back-end, SQL, CSS5, GitHub, Git, Node.js, Amazon Web Services (AWS), WebSockets, Full-stack, Unit Testing, Sideqik, jQuery, Express.js, Sidekiq, Scalability, Amazon RDS, MERN Stack, REST APIs, Jest, REST, CI/CD Pipelines, RESTful Services, Front-end, Rails Engines, AWS Lambda, Sass, Front-end Development, ECMAScript (ES6), Jenkins, API Development, Elasticsearch, API Integration, SendGrid API, Stripe API

Senior Full-stack Engineer

2013 - 2015

Stylesaint

Developed the entire order system of the application integrated multiple payment methods, including Stripe, PayPal, and Braintree.
Implemented a unified authentication solution for different web servers. Multiple applications can share the registration and authentication.
Oversaw the creation and maintenance of the company's AWS cloud server cluster.

Technologies: Backbone.js, Backbone.Marionette, Ruby on Rails (RoR), PostgreSQL, New Relic, CSS, APIs, Redis, Software Analysis, Software Testing, Human-computer Interaction (HCI), HTML, HTML5, Back-end, SQL, CSS5, GraphQL, MongoDB, Mocha, EJS, Haml, GitHub, Git, Node.js, Amazon Web Services (AWS), Spree, Stripe, Full-stack, Unit Testing, Sideqik, jQuery, TypeScript, Sidekiq, Scalability, Amazon RDS, JavaScript, RSpec, REST APIs, Heroku, CI/CD Pipelines, Front-end, Rails Engines, Sass, Front-end Development, API Development, eCommerce, API Integration, Stripe API

Senior Web Developer

2011 - 2014

Foxconn

Released our eCommerce app released, reaching the top three in the Apple Store Life category in Taiwan.
Led a team to design and develop the company's web server framework based on Ruby.
Oversaw the architecture of the eCommerce server. Created, tracked, and tested ticket development through project management tools.
Developed a high-speed eCommerce platform for OEM mobile phone companies. The number of orders generated per second exceeds 50,000.

Technologies: Node.js, Ruby, PostgreSQL, CentOS, APIs, Redis, Software Analysis, Software Testing, HTML, HTML5, Back-end, SQL, Full-stack, Unit Testing, Sideqik, MySQL, jQuery, Memcached, Sidekiq, JavaScript, Front-end, Rails Engines, Front-end Development, API Development, Google Maps SDK

Experience

MyFoodlink

Myfoodlink provides a fully hosted specialist online supermarket eCommerce platform for supermarkets and grocers. Myfoodlink can also help in website design and build, graphic design, sales and marketing, and shopping applications for smartphones.

Ezy Raise

https://www.ezyraise.com

Ezy Raise is a peer-to-peer fundraising platform provider, creating, maintaining, and supporting profiles for global charity organizations. Clients can customize the theme and feature and integrate third-party APIs (Fitbit, Garmin, etc.)

MLAPP

https://mlapp.com.au/

Mlapp.com.au is an Australia-based fintech project that helps users compare, save, and find a product among hundreds of financial institutions in Australia to suit users' needs.

I was the principal engineer for MLAPP and built the main structure of the front end and back end.

Forbes Q.ai

Q.ai is an AI-powered investing app from Forbes that lets you invest in a wide range of portfolios. Its unique selling point is that many portfolios have a hedging feature to provide downside protection. Portfolios also invest in a range of assets like stocks, ETFs, commodities, and crypto.

Mable

https://mable.com.au/

Mable is an online platform that connects people looking for disability and aged care support with independent support workers (mable.com.au/). It allows people to find local support workers and make choices around their care needs.

Launchpad

An AI-based React application that can use AI to help company employees complete some very specific jobs, like generating invoices, arranging events, estimating the cost, etc.

It can communicate with this company's existing project, which uses a microservices structure; the internal communication is via Kafka.

Education

2015 - 2017

Master's Degree in Computer Science

University of Wollongong - Wollongong, NSW, Australia

Skills

Libraries/APIs

React, Node.js, Backbone.js, REST APIs, EJS, Stripe, jQuery, Sidekiq, Rails Engines, API Development, Google Maps SDK, React Redux, Vue, Backbone.Marionette, Antd, SendGrid API, Stripe API

Tools

RSpec, Git, GitHub, Webpack, Spree, Slack, Mocha, Jenkins, Prisma, Zoom, Google Meet, Jira, RabbitMQ, Auth0, Figma

Languages

Ruby, JavaScript, CSS, HTML5, HTML, SQL, Haml, TypeScript, Sass, ECMAScript (ES6), GraphQL, Python, Rust

Frameworks

Ruby on Rails (RoR), Ruby on Rails 4, Bootstrap, Express.js, Tailwind CSS, Next.js, Capybara, Redux, Ember.js, Jest, Cypress, Angular

Paradigms

Unit Testing, REST, Software Testing, Human-computer Interaction (HCI), Microservices, Scrum, Agile

Platforms

MacOS, Sideqik, Google Cloud Platform (GCP), Ubuntu Linux, Linux, CentOS, Ubuntu, Amazon Web Services (AWS), Docker, Heroku, AWS Lambda, New Relic, Apache Kafka, Kubernetes

Storage

PostgreSQL, Redis, MongoDB, MySQL, Memcached, Google Cloud, Elasticsearch

Other

APIs, CSS5, Full-stack, Back-end, WebSockets, Full-stack Development, Scalability, RESTful Services, Front-end, Front-end Development, Technical Leadership, eCommerce, API Integration, Software Engineering, SEO Tools, Software Analysis, Pub/Sub, Amazon RDS, MERN Stack, CI/CD Pipelines, Serverless, Artificial Intelligence (AI), Planning

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