# John Kang

> Software Engineer at Cash App

Location: Brooklyn, New York, United States
Profile: https://flows.cv/johnkang

## Work Experience
### Senior Software Engineer @ Cash App
Jan 2025 – Present | New York City Metropolitan Area
A server engineer on Banking, Cash App Cards team

### Software Engineer @ Cash App
Jan 2023 – Jan 2025 | San Francisco, California, United States
A server engineer on Banking, Cash App Cards team
Led the end-to-end delivery of customer-facing features on Cash App Card, including:
  - GPS location consent trigger (60%+ opt-in during high-risk auth and card activation)
  - Customer-initiated card merchant blocking interface (5%+ improvement in transaction decline precision)
  - Revamped Cash App Card transaction receipts (in-app and email) with much richer transaction context to customers

Drove operational rigor through writing card transaction testing, covering 10+ patterns (auth,
capture, refund, etc), which can be used to safely validate code changes against staging before rollout to production.

### Software Engineer @ Coinbase
Jan 2021 – Jan 2023 | San Francisco, California, United States
SWE on Infrastructure, Reliability team
- Developed the traffic-based canary deployment system against production services to reduce the percentage of bad code release incidents
- Conducted load tests for Coinbase Web and QR Code to prepare for the 2022 Super Bowl Ad and collaborated with the Retail team to identify and remove performance bottlenecks
- Implemented and maintained the incident management tool (in-house application made with Slack bot) to support team/service-wide paging and re-shape the response process for major incidents

### Software Engineer Intern @ Coinbase
Jan 2020 – Jan 2020 | San Francisco, California, United States
- Implemented Slack commands to auto-generate the incident timeline and follow-ups by crawling the history of the Slack messages reacted by designated emojis, using Ruby as a language and Slack API
- Improved developer productivity by facilitating the write-up of postmortem documents

### Software Engineer Intern @ Coinone Labs
Jan 2019 – Jan 2019 | Yeongdeungpo-gu, Seoul, South Korea
- Created an integrated serverless API that sends and verifies e-mail/SNS/ARS authentication
- Deployed the API service into AWS API Gateway, S3, and SQS/SNS
- Built in JavaScript with Node.js and Express.js as web frameworks

### Software Engineer Intern @ Fasoo
Jan 2018 – Jan 2018 | Mapo-gu, Seoul, Korea
- Built a semantic model that recommends search words based on user’s frequently accessed documents
- Trained datasets from Fasoo’s document management software Wrapsody and advanced its accuracy to over 75 percent, using Python library Gensim 
- Applied the model to the search bar on the next release of Wrapsody

### Peer Tutor @ Duke University
Jan 2018 – Jan 2018 | Raleigh-Durham, North Carolina Area
- Tutored data structures and algorithms in Java to Duke students once a week
- Reviewed class materials and scheduled help sessions for Java


## Education
### Bachelor of Science - BS in computer science
Duke University
Jan 2014 – Jan 2020

### High School
Hankuk Academy of Foreign Studies
Jan 2011 – Jan 2014


## Contact & Social
- LinkedIn: https://linkedin.com/in/johngnak

---
Source: https://flows.cv/johnkang
JSON Resume: https://flows.cv/johnkang/resume.json
Last updated: 2026-03-20