https://www.pistack.xyz/tags/bytecode/ Recent content in Bytecode on Pi Stack Hugo en-us Fri, 11 Sep 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-09-11-jvm-bytecode-engineering-byte-buddy-javassist-asm/ Fri, 11 Sep 2026 00:00:00 +0000 https://www.pistack.xyz/posts/2026-09-11-jvm-bytecode-engineering-byte-buddy-javassist-asm/ <p>Something in your JVM is rewriting class files while your application runs. It might be your mocking library stubbing a final method, your APM agent weaving timers into service calls, or your ORM generating a proxy for lazy loading. Roughly 40% of the libraries in a typical Maven dependency tree touch bytecode at some point, and nearly all of them pick one of three tools to do it: <strong>Byte Buddy, Javassist, or ASM</strong>.</p>