Chang Min Park

Senior Software Engineer at Yahoo!

Course Research Personal Writing Systems Testing Security Linux Android DevEx Distributed Agents

Course

Advanced TCAM Design VLSI Electronics • Nov 2019
Immix Garbage Collection on Dart VM Advanced Programming Languages • Dec 2018
Automated Hand Model Realtime Embed Systems • Nov 2015

Research

On-Device Hyper-Personalization for Mobile Apps Patent • May 2026
RecoFlow: Recovering from Compatibility Crashes by Reusing User Flows Archived • Jun 2024
Crestone: End-to-End Image Integrity Archived • Oct 2023
Rushmore: Securely Displaying Static and Animated Images Using TrustZone MobiSys • Jun 2021
Gesto: Mapping UI Events to Gestures and Voice Commands EICS • Jun 2019
Mimic: UI Compatibility Testing System for Android Apps ICSE • May 2019
Reptor: Enabling API Virtualization on Android for Platform Openness MobiSys • Jun 2017
Auto Clicker MobiSys Demo • Jun 2017

Personal

Mocket App Android App • Sep 2018

Writing

When GitHub Actions Is the Outage • Aug 2026
Tickets Where an Agent Makes You Slower • Jul 2026
Making a Monorepo Navigable to Agents • Jun 2026
In-App Review Returned Success — The Dialog Never Showed • May 2026
The Chat That Forgot the Constraint — and the Memory That Gaslit the Fix • May 2026
Planning Theater vs a Plan That Saves a Rewrite • Apr 2026
Mobile Logs, Crashes, and Metrics: Pick Signals That Decide • Apr 2026
"It Worked Once in Chat" Is Not a Ship Bar • Mar 2026
Android FE Architecture History: MVC to Compose • Mar 2026
The Bot Commented on Your PR and Nobody Owns It • Mar 2026
ANR Stack Traces Lie by Omission — Crashlytics Is One Layer • Feb 2026
Your Agent Has Too Many Tools — and Mistakes Access for Expertise • Feb 2026
GHEC vs GHES: What Actually Changes for Your Team • Feb 2026
Imperative vs Declarative Android UI: What Migration Actually Changes • Feb 2026
The Overnight Agent PR Fantasy • Jan 2026
REST vs RPC: Same HTTP, Different Contracts • Jan 2026
Fat vs Chatty APIs on Cellular • Jan 2026
Agent Trust Boundaries: Approvals That Matter, Tools That Lie • Jan 2026
The Agent Said Done — and CI Is Red • Dec 2025
Replication Lag Filed as an Android Bug • Dec 2025
Building an AI Assistant Surface in Jetpack Compose Without Fighting the Keyboard • Nov 2025
Cache Invalidation from CDN to Room • Nov 2025
Subagents That Argue While You Pay for Both • Nov 2025
Redux on Android: When Unidirectional State Is Worth the Ceremony • Oct 2025
Gradle Modularization: Slice for Change, Not for the Diagram • Oct 2025
The Request Path Should Never Wait • Sep 2025
Three Clients, Same Aggregation: Why BFF Shows Up • Aug 2025
A Hot Mailbox Melts the Shard • Jul 2025
Types of Mobile Apps: When Native Still Wins • Jul 2025
Push Is a Distributed System, Not a FCM Call • Jun 2025
Feature Flags on Mobile: Kill Switch, Rollout, Experiment • May 2025
Scalable Patterns Worth Stealing (Without Renaming Your Résumé) • May 2025
One Telemetry Story Across Client and Server • Apr 2025
Mail Storage & Caching Without Lagging the Gesture • Mar 2025
Offline-First Mail: Consistency Is a UX Decision • Mar 2025
Multi-Region Reality for Mobile Users • Feb 2025
GitHub Actions for Android: PR Gates That Protect Merges • Feb 2025
Rate Limits Without Gaslighting the UX • Jan 2025
Retry Storms: When Your Own Clients DDoS You • Jun 2024
The API Is Up. Why Are Phones Still Broken? • Jan 2024
Memoization: Cache the Result, Not the Algorithm • Sep 2023
From Jenkins to Screwdriver: What CI/CD Actually Buys an Android Team • Aug 2023
Why Your PR Diff Is Noisy: Formatters vs Linters • Jun 2023
Web-to-App Install Prompts: When Nagging Costs Retention • Jun 2023
Image Security in General: What Breaks on the Mobile Photo Path • Apr 2023
Cross-Platform Mobile Frameworks: Flutter, RN, and the WebView Trap • Mar 2023
Android SDK Versions: compileSdk, minSdk, and targetSdk in Production • Dec 2022
Android Support Library → AndroidX: What the Old Stack Maps To Today • Nov 2022
Android Sandbox: UID Isolation and the Holes You Open Yourself • Oct 2022
Zombie vs Orphan Processes: What ps Is Actually Showing • Sep 2022
Primitive vs Reference Types: Memory, Boxing, and Kotlin Nulls • Jun 2022
Stack-Based vs Register-Based VMs: Why Dalvik Chose Registers • Apr 2022
OpenGL Rendering Pipeline: What Actually Breaks in Practice • Jul 2021
tee, Pipe, and Redirection: Watch Output While You Log It • Mar 2021
Hard Links vs Symbolic Links: Same Inode, Different Contract • Nov 2020
Android Architecture Breakdown: Which Layer Owns Your Bug? • Nov 2020
Linux Filesystem Hierarchy: Where Production Bugs Hide • Sep 2020
Software Testing Methods • May 2020
Interrupt Handling in OP-TEE: IRQ, FIQ, and World Switches • Mar 2020
White Box, Black Box, and Gray Box Testing • Nov 2019
Research Methodology: Qualitative vs Quantitative • Nov 2019
Dalvik and ART: What the Runtime Layer Still Explains • Sep 2019
Levenshtein Distance: Edit Cost for Typos and Fuzzy Match • Aug 2019

Systems

Memoization: Cache the Result, Not the Algorithm • Sep 2023
Primitive vs Reference Types: Memory, Boxing, and Kotlin Nulls • Jun 2022
Stack-Based vs Register-Based VMs: Why Dalvik Chose Registers • Apr 2022
OpenGL Rendering Pipeline: What Actually Breaks in Practice • Jul 2021
Dalvik and ART: What the Runtime Layer Still Explains • Sep 2019
Levenshtein Distance: Edit Cost for Typos and Fuzzy Match • Aug 2019

Testing

"It Worked Once in Chat" Is Not a Ship Bar • Mar 2026
Software Testing Methods • May 2020
White Box, Black Box, and Gray Box Testing • Nov 2019
Research Methodology: Qualitative vs Quantitative • Nov 2019

Security

Agent Trust Boundaries: Approvals That Matter, Tools That Lie • Jan 2026
Image Security in General: What Breaks on the Mobile Photo Path • Apr 2023
Android Sandbox: UID Isolation and the Holes You Open Yourself • Oct 2022
Interrupt Handling in OP-TEE: IRQ, FIQ, and World Switches • Mar 2020

Linux

Zombie vs Orphan Processes: What ps Is Actually Showing • Sep 2022
tee, Pipe, and Redirection: Watch Output While You Log It • Mar 2021
Hard Links vs Symbolic Links: Same Inode, Different Contract • Nov 2020
Linux Filesystem Hierarchy: Where Production Bugs Hide • Sep 2020

Android

In-App Review Returned Success — The Dialog Never Showed • May 2026
Mobile Logs, Crashes, and Metrics: Pick Signals That Decide • Apr 2026
Android FE Architecture History: MVC to Compose • Mar 2026
ANR Stack Traces Lie by Omission — Crashlytics Is One Layer • Feb 2026
Imperative vs Declarative Android UI: What Migration Actually Changes • Feb 2026
Building an AI Assistant Surface in Jetpack Compose Without Fighting the Keyboard • Nov 2025
Redux on Android: When Unidirectional State Is Worth the Ceremony • Oct 2025
Gradle Modularization: Slice for Change, Not for the Diagram • Oct 2025
Types of Mobile Apps: When Native Still Wins • Jul 2025
Feature Flags on Mobile: Kill Switch, Rollout, Experiment • May 2025
Mail Storage & Caching Without Lagging the Gesture • Mar 2025
Web-to-App Install Prompts: When Nagging Costs Retention • Jun 2023
Cross-Platform Mobile Frameworks: Flutter, RN, and the WebView Trap • Mar 2023
Android SDK Versions: compileSdk, minSdk, and targetSdk in Production • Dec 2022
Android Support Library → AndroidX: What the Old Stack Maps To Today • Nov 2022
Android Architecture Breakdown: Which Layer Owns Your Bug? • Nov 2020

DevEx

When GitHub Actions Is the Outage • Aug 2026
GHEC vs GHES: What Actually Changes for Your Team • Feb 2026
GitHub Actions for Android: PR Gates That Protect Merges • Feb 2025
From Jenkins to Screwdriver: What CI/CD Actually Buys an Android Team • Aug 2023
Why Your PR Diff Is Noisy: Formatters vs Linters • Jun 2023

Distributed

REST vs RPC: Same HTTP, Different Contracts • Jan 2026
Fat vs Chatty APIs on Cellular • Jan 2026
Replication Lag Filed as an Android Bug • Dec 2025
Cache Invalidation from CDN to Room • Nov 2025
The Request Path Should Never Wait • Sep 2025
Three Clients, Same Aggregation: Why BFF Shows Up • Aug 2025
A Hot Mailbox Melts the Shard • Jul 2025
Push Is a Distributed System, Not a FCM Call • Jun 2025
Scalable Patterns Worth Stealing (Without Renaming Your Résumé) • May 2025
One Telemetry Story Across Client and Server • Apr 2025
Offline-First Mail: Consistency Is a UX Decision • Mar 2025
Multi-Region Reality for Mobile Users • Feb 2025
Rate Limits Without Gaslighting the UX • Jan 2025
Retry Storms: When Your Own Clients DDoS You • Jun 2024
The API Is Up. Why Are Phones Still Broken? • Jan 2024

Agents

Tickets Where an Agent Makes You Slower • Jul 2026
Making a Monorepo Navigable to Agents • Jun 2026
The Chat That Forgot the Constraint — and the Memory That Gaslit the Fix • May 2026
Planning Theater vs a Plan That Saves a Rewrite • Apr 2026
The Bot Commented on Your PR and Nobody Owns It • Mar 2026
Your Agent Has Too Many Tools — and Mistakes Access for Expertise • Feb 2026
The Overnight Agent PR Fantasy • Jan 2026
The Agent Said Done — and CI Is Red • Dec 2025
Subagents That Argue While You Pay for Both • Nov 2025