Joohwan Oh, Developer in Vancouver, BC, Canada
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Joohwan Oh

Verified Expert  in Engineering

Software Developer

Vancouver, BC, Canada
Toptal Member Since
April 2, 2020

Joohwan has over eight years of professional experience in software development, specializing in distributed and back-end systems. His work history includes successful startups and big tech companies such as Amazon and Meta. Author of several popular open-source projects on GitHub, Joohwan works most often with Python, Django, and AWS.


Meta (Facebook)
Apache Thrift, Python, Infrastructure, MySQL, REST APIs, React, TypeScript
Amazon Web Services (AWS)
Amazon Web Services (AWS), Git, Python, Java, TypeScript
Amazon Web Services (AWS), Linux, Git, AngularJS, Java




Preferred Environment

Amazon Web Services (AWS), Linux, Git, Python, Django

The most amazing...

...experience I've had was from my open source projects, several of which made it to the front page of Hacker News and now have many users.

Work Experience

Software Engineer

2021 - PRESENT
Meta (Facebook)
  • Was a founding member of a critical back-end service for company-wide capacity management.
  • Designed and built highly scalable APIs and microservices using Thrift, Python, MySQL, and Hive.
  • Optimized one of the core microservices owned by the team and reduced its timeouts by 90%.
Technologies: Apache Thrift, Python, Infrastructure, MySQL, REST APIs, React, TypeScript

Software Development Engineer

2020 - 2021
Amazon Web Services (AWS)
  • Led a team of engineers to deliver multiple projects end-to-end, adding new scheduling features to Amazon Connect.
  • Designed and built highly scalable APIs, microservices, and data pipelines using AWS.
  • Mentored other software engineers and interns in the team regularly.
Technologies: Amazon Web Services (AWS), Git, Python, Java, TypeScript

Software Development Engineer

2017 - 2018
  • Designed and built software and video games platform features, part of retail website.
  • Overhauled the web portal for onboarding third-party software vendors.
  • Trained the new intern and oversaw his internship project.
Technologies: Amazon Web Services (AWS), Linux, Git, AngularJS, Java

Software Engineer

2015 - 2016
Unata (acquired by Instacart)
  • Integrated Unata's eCommerce platform with third-party services such as Salesforce and Paypal.
  • Optimized the daily client data ingestion process and reduced its runtime by 80%.
  • Wore many hats and played vital roles in the back end, DevOps, and client meetings while the company grew quickly from 10 to 50+ people in a year.
Technologies: Linux, Git, Amazon Web Services (AWS), Redis, PostgreSQL, Flask, Python

Software Engineer Intern

2013 - 2014
Demonware (Activision Blizzard)
  • Implemented features for an operations tool for automating datacenter management workflows.
  • Created plugins for the automation tool to interface with MySQL and ArangoDB.
  • Built a datacenter topology visualizer for an in-house hackathon.
Technologies: Linux, Git, ArangoDB, MySQL, Python

Original author and maintainer of Python-Arango. Python-Arango is the most popular Python driver for ArangoDB, a NoSQL graph database. The project started out as a hobby and gradually evolved into an official, production-ready library.

Author and maintainer of Binarytree, an open-source Python library that provides a simple API to generate, visualize, inspect, and manipulate binary trees. It lets users skip the tedious work of setting up test data and dive straight into practicing algorithms.

Kafka Queue (KQ)
Author and maintainer of Kafka Queue (KQ), an open-source Python library for enqueuing and processing jobs asynchronously using Apache Kafka as the back-end storage. The project received over 550+ stars on Github.


Python, Java, TypeScript


REST APIs, Node.js, React


Git, GitHub


Amazon Web Services (AWS), Linux, Docker, Apache Kafka


Django REST Framework, Django, Flask, AngularJS, Apache Thrift




PostgreSQL, NoSQL, Redis, ArangoDB, Databases, MySQL


Distributed Systems, Infrastructure

2010 - 2015

Bachelor's Degree in Computer Science

University of Toronto - Toronto, ON

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