THE HARD PART“Shipping voice at scale — async messaging, real-time delivery, and live voice agents on the same pipeline — from blank Figma to a Play Store launch in 40 days, entirely in-house, at Krafton's quality bar.”
Yeapp is voice at scale. An async voice messaging app built as a strategic partnership with Krafton — the publisher behind PUBG and a $1B+ gaming and consumer-tech company — designed to bring back the warmth of voice to everyday social communication while opening a new surface for AI-native voice experiences. Live now on Google Play.
The product is two things at once. On one side, a fast, beautifully simple way to send voice messages between friends and creators — push, talk, send, react. On the other, a platform for production-grade voice agents that listen, reason, and respond in real time. Both are powered by the same voice-at-scale backbone — one streaming pipeline carrying human-to-human messages and live AI conversations alike.
The defining constraint was speed. We shipped Yeapp from a blank Figma to a public Play Store launch in a 40-day sprint. That meant making opinionated architectural calls early: a streaming voice ingest path that keeps up with real users, an async messaging model that survives flaky mobile networks, a voice-agent runtime that can be slotted into any conversation, and an observability story tight enough to debug a low-latency audio stack at 2am.
Yeapp was built entirely in-house as a strategic partnership with Krafton — no external product or design agencies. I co-led the product with our Krafton partners and led the engineering team end-to-end: overall architecture, the voice-at-scale pipeline (ingest, transport, transcription, TTS, agent orchestration), the cloud and data infrastructure, the API surface for both the mobile client and the agent runtime, and the launch and on-call discipline that got us to Play Store in 40 days. Marketing site: yeapp.live. Play Store: play.google.com/store/apps/details?id=com.kinvrs.yeapp.
