Bonsung - Software Engineer
I have beenbuilding software professionally since 2016,from an international reference implementation of an image standard to an app used by 300,000 people across 15 countries.
I wasa lead engineer for three years,and more recently I have engineered a full web product,from its React front end to its .NET backend on Azure.
I doagentic AI engineering,building the development environment our coding agents work in.
Work Experience

airie
🧑💻
Senior Software Engineer (part-time to December 2025, full-time since)
July 2025 ~ Present (1 year, 3 months)
• Engineered a customer-facing web platform for immigrants with React, TypeScript and Vite, then took on its .NET backend and built its design system and the Figma workflow around it.
• Designed and executed a multi-phase migration of the entire product onto Azure, retiring the previous platform's data layer, API and front-end integration in staged releases with no interruption to service.
• Wrote unit, component and integration tests, including end-to-end tests that run against a real database and API, with Vitest, React Testing Library, Playwright and xUnit.
• Defined the Azure infrastructure for a background notification service as code in Bicep, and deploy the product through GitHub Actions to separate development, staging and production environments.
• Moved Azure OpenAI access from API keys to Entra ID managed identities, and rebuilt the previous platform's row-level permissions as role-based access control in the API.
• Built the agent-operated development environment that production work ships through every day, with per-repository agent instructions, a specification-first workflow, and a categorised knowledge base that makes previously solved problems retrievable.
• Mentored an intern developer through an 8-week programme that ended with a production-ready feature they shipped themselves.

Shopl and Company
🧑💻
Lead & Senior iOS Engineer
August 2021 ~ June 2024 (2 years, 11 months)
• Engineered and scaled a native iOS app (Shopl) for task management, serving 300,000+ employees in 60,000 workplaces across 15 countries.
• Introduced Modular and Clean Architecture to the codebase, led the team's move to a new UI framework, and led the migration of a critical legacy system everyone considered untouchable, retiring it completely.
• Built the company's first CI/CD pipeline with GitHub Actions and its first automated test suite, moving QA from monthly to weekly cycles with every production crash traceable to its line of code. Optimised app performance with profiling tools.
• Built and led a team of three software engineers in two-week Agile sprints, ran code reviews with them, mentored two engineers, and co-authored the team's iOS coding standards.
• Represented engineering in weekly leadership meetings, showing the expected outcomes of technical improvements with data so non-technical stakeholders could weigh the trade-offs.

PJ FACTORY Co., Ltd.
🧑💻
Intermediate iOS Engineer (Junior to September 2018)
October 2016 ~ June 2021 (4 years, 9 months)
• Developed an iOS app (Detail) to create and manipulate images in the new DTL (JLINK / JPEG Systems Part 7) format, serving as the official reference software for the standard.
• Applied functional and reactive programming alongside MVC and MVVM, and owned the end-to-end iOS lifecycle, including every App Store submission and release.
Projects
airie
React

TypeScript
Vite
.NET
Azure

Bicep
GitHub Actions
Playwright
Figma
• A customer-facing web platform for immigrants.
• A React and TypeScript front end, and a C# .NET backend on Azure SQL with Azure infrastructure written in Bicep.
• Built the agent-operated development environment that production work ships through every day.
• Migrated the whole product onto Azure with no interruption to service.
• Adopted Feature-Sliced Design (FSD).
It started as a prototype that proved the idea, and my job has been to make it last: the inherited code kept running and new features kept shipping while the platform moved underneath it.
Took on the .NET backend and then the platform migration, moving visa-admission data, commission rates and user and agent records onto Azure in staged releases, and retiring the previous platform once the front-end no longer depended on it.
Refactored and migrated key UI components from a legacy monolith to a modern front-end architecture in the new airie application, increasing developer velocity and reducing technical debt.
Built the product's design system and the Figma workflow around it, so design and engineering assemble screens from the same set of components.
Wrote unit, component and integration tests, including end-to-end tests that run against a real database and API.
Moved Azure OpenAI access from API keys to Entra ID managed identities, and rebuilt the previous platform's row-level permissions as role-based access control in the API.
Built the agent-operated development environment that production work ships through: every repository carries its own instructions for the coding agents, work starts from a written specification rather than a prompt, and a categorised knowledge base keeps previously solved problems retrievable.
Mentored an intern developer through an 8-week programme that ended with a production-ready feature they shipped themselves.
Shopl
Swift

Objective-C

SwiftUI
UIKit

TCA

RxSwift

Tuist
Swift Package Manager

XCTest

Firebase
GitHub Actions
fastlane
• Served 300,000+ employees in 60,000 workplaces across 15 countries.
• Adopted Clean Architecture and Modular Architecture.
• Adopted MVVM design pattern with the reactive programming paradigm.
• Worked with business stakeholders on white-labelled apps and client-specific features sold under separate contracts.
Introduced Modular Architecture with Tuist and Swift Package Manager that made builds 7.5 times faster, and Clean Architecture with MVVM that lifted team productivity by over 50% through code reuse.
Led the migration of a critical Objective-C legacy system to Swift, a codebase the team treated as untouchable, making it manageable within a year and retiring it completely within two, without affecting the quality of the product.
Drove the team's transition to SwiftUI from 2023 while keeping the UIKit codebase in maintenance.
Eliminated a lag in the face recognition clock-in on first open, using the Time Profiler in Instruments to trace it to a heavy singleton initialising synchronously on the main thread, then moving that initialisation to a background thread.
Engineered a fully automated CI/CD pipeline with GitHub Actions and fastlane, cutting the average release time from 2 hours to just 20 minutes and moving QA from monthly to weekly cycles.
Initiated and led the company’s first automated testing strategy for iOS, building test coverage from the ground up to 30% and significantly improving release stability.
Gave product, design and sales teams preview builds from the pipeline, so their feedback reached us before release.
Localised the app into 10 languages for business expansion and automated the process.
Established a white-labelled app system for enterprise clients.
Represented engineering in weekly leadership meetings, showing the trade-offs of technical work with data.








Detail – Stories in Image

App Store · apps.apple.com/us/app/detail-stories-in-image/id1468063860
Swift
UIKit

RxSwift

Firebase

Xcode Server Bots
fastlane
• The official reference software for the DTL (JLINK / JPEG Systems Part 7) image standard.
• Adopted MVC and MVVM design patterns.
• Applied functional and reactive programming techniques to architect a more resilient codebase, improving application stability and simplifying the management of data flows.
• Worked closely with the design and backend team to deliver the best user experience.
• Available only on the Korean, Japanese and US App Stores.
Built to create and manipulate images in the then-new DTL format (JLINK / JPEG Systems Part 7), and adopted as the official reference implementation for the standard itself.
Implemented modern architectural patterns, including MVVM, to decouple components and improve code clarity, leading to a more maintainable and efficient development cycle.
Crafted intuitive and responsive user interfaces using UIKit and AutoLayout, strictly adhering to Apple’s Human Interface Guidelines to deliver a polished and optimal user experience.
Configured Xcode Server Bots (since replaced by Xcode Cloud) for continuous integration and deployment.
Localised the app into Korean, English and Japanese, and automated the process.





Personal Projects

TypeScript

Node.js
Cloudflare Workers
Durable Objects
MCP
GitHub App
• AI-powered GitHub issue fixer, issues in and pull requests out.
• Designed and built the whole system solo.
• Test-driven by rule.
A Cloudflare Worker receives GitHub App webhooks and relays them through a Durable Object to a local MCP server running inside Claude Code, which spawns headless Claude sessions to investigate issues, implement fixes and open pull requests.
Built to run unattended, which meant scoping each task narrowly enough for a session to finish it without supervision, and handling the failures rather than watching for them.
No production code written before a failing test, and every bug fix ships alongside the regression test that catches it.

TypeScript
React
Vite

FSD
MUI

Tailwind CSS

Node.js

Express

Firebase
GitHub Actions
Swift

SwiftUI
Combine

Tuist

Xcode Cloud
• Solo-built consumer product, iOS plus web plus API.
• Tuist modular architecture, with credentials kept out of the repository.
• Service retired in 2026, source remains public.
Designed, built and shipped an iOS app to the App Store, together with its Node.js API (Express on Firebase Functions, with Firestore, a NoSQL database) and TypeScript web front-end, all three tiers single-handedly.
Tuist modular architecture with build configurations separated behind protocols so credentials never entered the repository, plus Xcode Cloud CI, dark mode and localisation.




Education
🎓
Master of Information Technology
July 2024 ~ October 2025
Whitireia and WelTec
Wellington, New Zealand
🎓
Bachelor of Engineering in Computer Science
March 2006 ~ February 2015
The University of Suwon
South Korea