Dave Hyungmok Lee, Developer in Seoul, South Korea
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Dave Hyungmok Lee

Verified Expert  in Engineering

Python Developer

Seoul, South Korea
Toptal Member Since
December 30, 2014

Dave Hyungmok is a self-motivated and goal-oriented professional committed to pursuing a long-term career in computer engineering. He created several fully functional apps for Android devices, one of which has ranked #1 in the Korean Android market. Dave Hyungmok is known for writing efficient, maintainable, and reusable code and has strong development and problem-solving skills.


Grip Company
JavaScript, AWS IoT, Python 3, React, Next.js
Python 3, JavaScript, Node.js, Vue, Amazon Web Services (AWS)...
Calm Island
Amazon Web Services (AWS), Jenkins, Git, JavaScript, Python, Java




Preferred Environment

Linux, OS X, Visual Studio Code (VS Code)

The most amazing...

...thing I've successfully launched is a seller application for eBay, enabling users to see how garments look on an avatar before purchase.

Work Experience

Tech Synergy Team Lead

2023 - 2024
Grip Company
  • Participated as a liaison between the team and other Kakao affiliates during deal negotiations, fostering collaboration and effective communication.
  • Orchestrated the strategy for seamless migration to AWS Cloud, optimizing cloud infrastructure and operations.
  • Incorporated software engineering best practices such as code review, PRD, design spec, elevating product quality, and development standards.
  • Contributed more than 1% of total transaction amount through e-coupon API integration.
  • Orchestrated communication and information sharing between internal development teams and external partners, ensuring seamless collaboration and efficient project execution.
  • Led project planning, scheduling, implementation, resource allocation, and progress tracking in collaboration with internal development teams and external partners, guaranteeing on-time, on-budget project deliveries.
  • Collaborated with internal and external stakeholders to gather and analyze project requirements while preparing essential documentation for development.
  • Identified potential risks and issues in collaborative projects and developed risk mitigation strategies and contingency plans to address issues throughout the project lifecycle.
Technologies: JavaScript, AWS IoT, Python 3, React, Next.js


2021 - 2022
  • Led a Cloud-based SaaS app development as a tech lead.
  • Developed the SaaS app as a tech lead with hands-on skills.
  • Worked with multi-cloud platforms such as GCP, Google Firebase, and AWS for the SaaS app development.
  • Utilized Agile methodologies such as Scrum, sprint, and retrospective.
  • Made use of software engineering methodologies such as code reviews and design specs.
Technologies: Python 3, JavaScript, Node.js, Vue, Amazon Web Services (AWS), Google Cloud Platform (GCP), Firebase

Tech Lead

2018 - 2020
Calm Island
  • Led tech initiatives on the adaptive learning platform.
  • Led multiple projects, such as the mobile apps and data pipeline project simultaneously, targeting many countries such as China, Sri Lanka, and Vietnam.
  • Managed 15 back- and front-end engineers as a tech lead.
  • Designed and led a big data platform targeting customers in many countries.
Technologies: Amazon Web Services (AWS), Jenkins, Git, JavaScript, Python, Java

Tech Lead

2018 - 2018
  • Led tech initiatives on the big data/machine learning platform, ingesting eight million events daily.
  • Supported multiple large companies using the big data platform in Korea.
  • Communicated between software engineers working at HQ and Korean customers.
  • Designed and coded APIs for customers in Korea and reduced development costs to 50%.
Technologies: Amazon Web Services (AWS), HBase, Jenkins, Git, Apache Kafka, Python, Java

Senior Software Engineer

2014 - 2017
Ziontech Korea
  • Provided a solution to the challenge of the same UI as the existing heavy traffic iPhone app by designing and developing an Android application as a lead.
  • Enabled messaging between components throughout the entire architecture by developing a message-producing broker library with Kafka.
  • Provided a solution to SSO development needs by customizing an open-source software CAS.
  • Reduced costs for back-end API development by 50% by refactoring an open-source project, eSCIMo, and debugged existing bugs earlier than scheduled.
  • Managed, assigned, and communicated programming tasks to teams of engineers in the US, Korea, and India branches in a multi-lingual environment.
Technologies: SQL, Docker, Jenkins, GitHub, Apache Kafka, JavaScript, Java

PHP Developer

2015 - 2015
Adam Fordham Consulting (via Toptal)
  • Created website administrator modules using PHP, MySQL, and JavaScript.
  • Created front-end modules using JavaScript, jQuery, and Bootstrap.
  • Improved the performance of SQL and performed query optimizations.
  • Created a back-end payment module using PHP and CakePHP.
  • Improved the existing payment modules.
Technologies: Bootstrap, MySQL, JavaScript

Project Manager

2013 - 2014
ESES Global, Inc.
  • Designed and implemented an Android app, providing guesthouse information.
  • Helped the app succeed as the number one app in the new free app section of Google Play Store.
  • Acquired +30,000 users in three months after launch with Facebook marketing.
  • Designed and implemented a search engine website providing job information for expatriates living in South Korea.
  • Acquired dispersed job information from Korea to give job seekers access to tons of job information with one search.
Technologies: MongoDB, Yii, LAMP, Android

Java Developer

2012 - 2012
Samsung SDS (Contract)
  • Implemented SAP EP modules reflecting company-wide requirements of Samsung.
  • Designed front-end web pages for the responsive web requirements.
  • Enabled functionality on all other modern browsers, unlike the previous version which had only been available on IE.
Technologies: Java

Senior Software Engineer

2010 - 2011
Outspark, Inc.
  • Increased work efficiency of the PM and GM by developing a new CMS for web content management.
  • Improved front-end rendering performance by 30% by deploying a new client-side platform for all game websites.
  • Improved back-end performance by creating a replacement of the existing server-side platform.
Technologies: MySQL, JavaScript

Team Leader

2008 - 2010
G&G Commerce
  • Designed, developed, and successfully launched an innovative web avatar application on eBay, which displays cyber garments. Users could search for items on the website by mapping cyber garments on an avatar using the application. The company could get paid as an eBay affiliate through this application because this application advertises eBay sellers' items as a search result. This application enables sellers to earn net profits by putting it into their websites and blogs, reflecting customers' needs.
Technologies: MySQL, JavaScript

Front-end Engineer

2007 - 2008
Yahoo Korea
  • Developed various Yahoo Korea portal web pages.
  • Designed and implemented games using JavaScript.
  • Constructed an intuitive game interface for the Korean market, which resulted in a positive user experience and high user engagement.
Technologies: JavaScript

EdTech Kidaptive ALP

Kidaptive's Adaptive Learning Platform (ALP) has AI-based algorithms that empower educational companies to use the data they collect to increase learner engagement and improve outcomes. I worked on the ALP as tech lead using a tech stack including Java, Hadoop ecosystems, and Python.

Wavity Cloud SaaS Application

Enterprise cloud platform with reusable cloud applications that enables rapid development of new applications on the cloud, especially business-specific applications that leverage communications and collaboration.

API-driven Cloud Services (ACS) – An abstraction layer for integration with classes of cloud applications

Identity Cloud Services (ICS) – A centralized identity service to enable SSO

Mobile Cloud Services (MCS) – to deliver push notifications,
real-time analytics, and reporting for visibility

I worked on SSO and the REST API as well as the Android mobile app.

Wavity OneTeam Android App

OneTeam is a companion mobile app that can be used with the Wavity cloud platform and applications.

Simple yet powerful tools in OneTeam enable you to create ad-hoc teams where individuals from within your company as well as outside your company come together to get work done.

Key Features:
• Perform all end user and administrator functions on the mobile app
• Communicate, collaborate, and use business applications to get work done
• Receive push notifications – be informed or take actions based on notifications
• Access a centralized view of data relevant to you - as defined by you

You must be a user/customer of Wavity’s web-based service to use the mobile app.

For more information, please visit https://wavity.com

Pentui Android App

An Android app which provides pension information for South Korea. I designed and implemented the app and negotiated deals and terms with KTCS for a business development based on the product. The app has been ranked as the #1 app in the new free app section of the Google Play store and in the Travel & Local category.


A website focused on providing job information for expatriates in Korea. Since 2014, KoreaJob4expats has given job seekers free access to millions of jobs from hundreds of company websites and job boards.


SQL, JavaScript, Python, Java, Python 3


Bootstrap, Django, Flask, Django REST Framework, Next.js


REST APIs, Vue, Node.js, React


Linux, Firebase, Docker, Kubernetes, Amazon Web Services (AWS), AWS Lambda, OS X, Apache Kafka, Visual Studio Code (VS Code), Google Cloud Platform (GCP), AWS IoT


JSON, MySQL, Amazon DynamoDB, Amazon S3 (AWS S3), HBase


AWS Cloud Architecture, Software Engineering, Windows 10, Computer Engineering


Unit Testing


GitHub, Jenkins, Git

2011 - 2013

Master of Engineering Degree in Software Engineering

Sogang University - Seoul, Korea

2007 - 2010

Bachelor's Degree in Computer Engineering

Tech University of Korea - Seoul, Korea


AWS Cloud Architect Nanodegree



Essential Cloud Infrastructure: Core Services



Elastic Cloud Infrastructure: Scaling and Automation



Elastic Cloud Infrastructure: Containers and Services



Google Cloud Platform Fundamentals: Core Infrastructure



Essential Cloud Infrastructure: Foundation


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