Between is the global No.1 private SNS for couples with 35M+ users worldwide — a private space for chat, albums, and anniversary management where two people safely keep their memories together.
Client
VCNC
Year
2023
Scope
Android Development (All Frontend, 3-person team)
Platform
Android · Kotlin · RxJava · Retrofit · MVVM
The Challenge
Legacy stack (ButterKnife, AsyncTask, RxJava1) had to be migrated incrementally while the live service kept running, ad revenue (eCPM) had to be optimized without harming UX, and crashes / memory leaks had to be eliminated on the latest Android OS versions.
Our Solution
Migrated legacy code to ViewBinding / Coroutines / Flow, tuned AdMob waterfall strategies and ad-timing logic, designed House-Ad fallback scenarios via A/B testing for no-fill situations, fixed runtime crashes and memory leaks, and built reusable popup / bottom-sheet / tooltip modules shared across the org.
Results
Sustained 99%+ crash-free rate in live operation, continuously improved eCPM via ad-network optimization, reduced expected revenue loss during no-fill with A/B-tested fallbacks, cut build time and dev lead-time by cleaning up legacy code, and dramatically accelerated new-screen development with the shared UI module.