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Lucas Lee
Verified Expert in Engineering
Front-end Developer
Auckland, New Zealand
Toptal member since June 28, 2022
Bio
Lucas is a full-stack engineer with 10+ years of experience in web development, managing all aspects of the development process and mastering the front-end field. He is a great team player with an extensive background in mentoring fellow developers. Passionate about solving problems for his clients, Lucas's work focuses on creating an easy development environment, resolving technical debts, and providing best practice code examples.
Portfolio
MyWave
Java, Google Cloud Platform (GCP), Amazon Web Services (AWS), Gradle...
Daniel Fink
React, TypeScript, Full-stack Development, UI Components, BlockNote, Zustand...
Vector
Behavior-driven Development (BDD), Cucumber, React, Enzyme...
Experience
- Java - 10 years
- JavaScript - 10 years
- JUnit - 10 years
- React - 6 years
- Puppeteer - 3 years
- GraphQL - 3 years
- Jest - 3 years
- React Testing Library - 2 years
Preferred Environment
MacOS, PhpStorm, IntelliJ IDEA, Slack, Git
The most amazing...
...things I've built are an eCommerce site Coupang, number one in South Korea, and New Zealand's new energy platform.
Work Experience
Senior Softwave Engineer
2023 - PRESENT
MyWave
- Integrated DyFlex requirements into MyWave's interactive solution via a demo app. Users input data for DyFlex-managed orders in the MyWave interface, which is transmitted to the DyFlex server via a DyFlex API in the Google Cloud Platform (GCP).
- Incorporated MyWave with the DVS system to synchronize everything related to the movement of trade credit documents from the applicant to the guarantor and the beneficiary using RAmazon RDS, Amazon EC2, load balancers, and Amazon Route53.
- Led the integration of the Australian Venue Co reservation system with the MyWave solution. All the extensive data stored in Excel was successfully loaded into the RDS using the Amazon EC2 load balancer and Amazon Route53.
- Built the demo projects using Packer into AMI or GCP images, and instances were created and deployed on GCP or AWS.
Technologies: Java, Google Cloud Platform (GCP), Amazon Web Services (AWS), Gradle, Apache Maven, Bamboo, Docker, Docker Compose, JUnit, Mockito, Spring, Spring Boot, RESTful Web Services, PostgreSQL, Figma, Agile, Packer, WireMock, Large Language Models (LLMs), ChatGPT API, OpenAI API
React Consultant/Developer
2025 - 2025
Daniel Fink
- Developed a reactive documentation platform that integrates a Notion-style block editor with an Excel-like calculation engine, enabling users to create dynamic reports with real-time data visualization.
- Streamlined bug tracking and task management using GitHub Issues integrated with the development workflow.
- Led the end-to-end front-end development, resulting in the successful delivery of a complex MVP with rich-text and calculation features within a 4-month timeline.
- Collaborated closely with back-end engineers to design efficient RESTful API schemas, ensuring seamless data synchronization between the React front end and Python engine.
Technologies: React, TypeScript, Full-stack Development, UI Components, BlockNote, Zustand, Mantine, Docker
Senior Software Developer
2021 - 2022
Vector
- Built the new energy platform, mainly focused on the UI part of the operator interface so that operators can verify and modify all data through this website.
- Implemented back-end services using AWS Lambda and Java.
- Ran the acceptance tests using Cucumber BDD and Selenium.
- Achieved 100% code coverage for the front-end and back-end services using Jest and JUnit.
- Implemented a website for operators to handle all data through it using React, TypeScript, MUI, JWT, Figma, and so on.
Technologies: Behavior-driven Development (BDD), Cucumber, React, Enzyme, React Testing Library, Java 11, AWS Lambda, JUnit, Selenium, Material UI, Apache Maven, Test-driven Development (TDD), Jest, TypeScript, JSON Web Tokens (JWT), Testing, UI Development, Figma, WireMock
Senior Software Developer
2021 - 2021
Freelance
- Developed an admin website—admin.kaircargo.com/—for Korean people who live in South Korea or New Zealand.
- Built the website so that it manages inventory, flights, warehousing, invoice, order, and customers.
- Used Axios to send and receive data to and from the server, the communication method was a RESTful API, and authentication was handled with JWT.
Technologies: JavaScript, React, Recoil, CSS, HTML, REST, Axios, JSON Web Tokens (JWT), PrimeReact, Emotion API
Senior Software Developer
2019 - 2021
Write That Essay
- Joined a growing organization to deliver the next major iteration of their online writing tool for schools in New Zealand and Australia.
- Renewed the website and wrote solutions with my teammates. This tool has many features such as schools, classes, assignments, assessment, marking, graphs, etc.
- Created the front end using new technologies such as React, Emotion, visx, GraphQL, Apollo Client, SCSS/SASS (Syntactically Awesome Style Sheets), and others.
- Developed the back end using PHP, Silverstripe CMS, GraphQL, MySQL, and Docker.
- Opened Write That Essay WTE 2.0, a single-page application (SPA), in February 2020 and have been maintaining it daily.
- Implemented the home user payment gateway Writer's Toolbox, allowing the company to sell the product to the public in 2020. Also used the Stripe API to support payment.
Technologies: React, HTML, CSS, Sass, Emotion API, Visx, GraphQL, React Apollo, SilverStripe, MySQL, Docker, Amazon EC2, Jest, Puppeteer, React Testing Library, Stripe API, Enzyme, Slate, TypeScript, PHP, SQL, JSON Web Tokens (JWT), Adobe Experience Design (XD), Drag & Drop
Senior Software Developer
2018 - 2018
EasyForms
- Created the Korean Waterski Association website (kwwa2018.cafe24.com) with another developer in charge of HTML/CSS.
- Designed the whole project and database and implemented front-end and back-end features.
- Used Webpack, npm, SASS, jQuery, Dropzone.js, CKEditor, PHP, Laravel, Eloquent, MySQL, Nginx, FastCGI Process Manager (FPM), and Ubuntu on DigitalOcean.
Technologies: Laravel 5, jQuery, MySQL, NPM, Sass, CKEditor, NGINX, FPM, HTML, CSS, DigitalOcean, PHP, SQL, JSON Web Tokens (JWT)
Senior Software Developer
2017 - 2017
Gyeonggi-do Provincial Institute for Lifelong Learning
- Gathered lecture information by parsing HTML from 31 satellite cities' websites and saved them into MariaDB.
- Used Puppeteer to travel and scrape data from the websites.
- Provided those data in JSON format to the Gyeonggi-do Provincial Institute for Lifelong Learning, which wants to gather all the information in one place to serve the public. So we used PM2 with Node.js and also Apache to service it.
Technologies: Node.js, PM2, Linux, MariaDB, Apache2, Puppeteer, MySQL, SQL
Senior Full-stack Developer
2013 - 2017
Coupang
- Developed and implemented a discount coupon and cash system by assembling a tool that operators can use to design promotions and discount coupons and a batch that encourages customers to use their cash for imminent expiration dates in three days.
- Built a pricing comparison system that operators use to compare the company's products with the products of its main competitors utilizing a Chrome extension. The system compares the prices every hour and changes them automatically.
- Created a regular subscription products system that required improving front-end pages for PC and mobile web, implementing and adding some functions to the Android app with A/B testing, and developing a cart for subscription products.
- Implemented a product merging back-end tool that refines product data received from product suppliers that operators use to merge product data with existing products or create new ones.
- Developed and maintained a coupon (ticket) system and external APIs for suppliers on AWS.
- Designed and developed messaging templates back-end tool (MMS, SMS) for the business team using React, Babel, Webpack, Spring, Hibernate, and a Relational Database Service (RDS).
Technologies: Java 8, Spring 4, React, HTML5, CSS, Webpack, Agile, Amazon Web Services (AWS), Babel, Hibernate, MySQL, jQuery, Memcached, RabbitMQ, eCommerce, SQL
Senior Software Developer
2009 - 2013
OPASnet
- Developed and designed the Family Story I PC web project for Samsung on AWS as the lead developer and architect of the project.
- Built the Family Story II API project for Samsung, designed the global synchronization architecture, and provided APIs to various applications such as TV, PC, smartphone, and tablet, on AWS.
- Designed and developed the open API gateway system of the Samsung personal cloud project, the security framework open API routing architecture, internal and external, and access control, both authentication and authorization.
- Led the team for the business support system of the Samsung Bada platform while designing and developing the product cost management system.
Technologies: Java, JavaScript, HTML, CSS, Performance, MySQL, Oracle, SQL, Jakarta Server Pages (JSP), Spring, JSTL
Experience
Number One eCommerce Site in Korea
Coupang (http://coupang.com) is one of the biggest eCommerce companies in Korea that sells everything, like AliExpress. I worked as a senior full-stack developer and implemented several solutions, such as:
• Coupon (ticket) system
• Product merging tool
• Regular subscription products system
• Pricing comparison system
• Discount coupon system
• Coupon (ticket) system
• Product merging tool
• Regular subscription products system
• Pricing comparison system
• Discount coupon system
Writer's Toolbox
https://www.wtbox.comThe writer's toolbox is an advanced educational writing tool for parents who want to teach their children how to write essays and monitor their writing and homework. I worked as a senior full-stack developer and implemented a payment system using the Stripe API alongside two other junior members.
K-aircargo
A React-based website for an air cargo system. I was the front-end developer for the admin website to integrate a back-end server that provides RESTful API so administrators can manage inventory, flights, warehousing, invoices, orders, customers, and exchange rates.
Education
2017 - 2018
Postgraduate Diploma in Business Information Systems
UUNZ Institute of Business - Auckland, New Zealand
2008 - 2010
Master of Engineering Degree in Information Technology
Dankook University - Yongin, Gyeonggi, South Korea
Skills
Libraries/APIs
React, JSTL, jQuery, Node.js, Puppeteer, React Testing Library, REST APIs, PrimeReact, Emotion API, OpenAI API, Stripe API, Highcharts, Mantine
Tools
PhpStorm, IntelliJ IDEA, Figma, Adobe Experience Design (XD), Slack, Webpack, Babel, NPM, React Apollo, Cucumber, Git, Docker Compose, WireMock, RabbitMQ, PM2, CKEditor, NGINX, FPM, Apache Maven, Gradle, Bamboo, Packer
Languages
Java, JavaScript, HTML, GraphQL, TypeScript, CSS, Java 8, HTML5, Sass, Java 11, SQL, PHP
Frameworks
Laravel 5, Jest, JUnit, Jakarta Server Pages (JSP), Spring, JSON Web Tokens (JWT), Mockito, Spring 4, Hibernate, Selenium, Material UI, Recoil, Spring Boot, SilverStripe, Bootstrap
Paradigms
Agile, REST, Test-driven Development (TDD), Behavior-driven Development (BDD), Testing
Platforms
MacOS, AWS Lambda, Oracle, Amazon Web Services (AWS), Linux, Apache2, DigitalOcean, Docker, Amazon EC2, Google Cloud Platform (GCP)
Storage
MySQL, Memcached, MariaDB, PostgreSQL
Other
Axios, UI Development, Full-stack Development, Enzyme, Slate, eCommerce, Performance, Drag & Drop, RESTful Web Services, Large Language Models (LLMs), ChatGPT API, Business to Business (B2B), Information Systems, Computer Science, Visx, Hibernate 3, UI Components, BlockNote, Zustand
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