Stability is one of the three most important metrics for Coupang apps in providing a Wow customer experience. The mobile app monitoring platform aims to provide a reliable, easy-to-use, high extensibility monitoring platform for Coupang family apps. The platform supports not only mobile apps but web apps. The platform is based on the Lumberjack logging system and supports high-performance real-time stack trace de-obfuscation and symbolication within a few milliseconds (the industry standard is in hours). Thus, it is able to detect the issue within 3 mins and identify the root cause within 2 mins. Its high extensibility allows us to build more QoE/QoS metrics.