SkyWalking has just graduated as Top Level Project in this year. SkyWalking is an open source APM system, including monitoring, tracing, diagnosing capabilities for distributed systems in Cloud Native architecture. In the modern world, we have legacy and cloud-native distributed systems, even in hybrid. SkyWalking provides different observability methods, including language agents and service mesh angle, which adopt different scenarios. In this session, I will introduce what SkyWalking do, and how we do it, even without requiring any big data tech. A lightweight and powerful observability platform provides the core features of APM system.