This paper presents a flexible and modular approach to dynamic program analysis for JVM-based languages, aiming to address the limitations of existing tools, in particular their limited expressivity and tight coupling between instrumentation and analysis. The proposed solution decouples these two processes using BISM, a lightweight instrumentation language, and BeepBeep, a complex event processing engine. This novel combination enhances expressiveness, promotes reusability, and integrates seamlessly into JVM-based projects. Various analyses such as monitoring, profiling, coverage measurement, and complex event generation are demonstrated, showcasing the approach's flexibility.