How we improved APM Java startup by encoding a prefix trie as a JVM constant

To improve Java application startup performance, Datadog's APM team reduced class-matching overhead by 30% by optimizing how classes are selected for instrumentation. They achieved this by replacing complex runtime structures with `ClassNameTrie`, a prefix trie encoded as a single JVM string constant. This allows for rapid, I/O-free prefix matching during the critical `premain` phase when the JIT compiler is not yet active.