#spring

2 posts

Tech Feb 19, 2026

Understanding Tracing (5) – Java Agent vs Library Instrumentation

Comparing how the Micrometer (library) approach and the OTel Java Agent (bytecode manipulation) approach work — a look inside premain, the Instrumentation API, and ByteBuddy code injection.
Tech Feb 13, 2026

Understanding Tracing (4) – Kotlin Coroutines and Context Propagation

How to propagate context in coroutines, where the thread can change at every suspend point — the structure of CoroutineContext, ThreadContextElement, and bridging ThreadLocal with asContextElement().