Java's built-in Dynamic Proxies are limited to interfaces, creating a barrier for proxying concrete classes like Spring beans. To overcome this, developers rely on bytecode manipulation libraries. Historically, CGLIB dominated this space by generating subclasses, but it relied on 'dirty' tricks like sun.misc.

Unsafe to bypass constructors. This approach breaks encapsulation and causes errors in modern Java versions (9+). The industry has shifted to Byte Buddy, created by Rafael Winterhalter.

Byte Buddy uses a fluent API to generate proxies safely, adhering to JVM rules without bypassing security. It offers surgical precision in method interception, making it the standard for modern frameworks.