A classloader executing in an execution environment, such as a JAVA virtual machine or a software container, may be configured to generate class usage data describing the historical usage of classes by applications in the execution environment. Based upon the class usage data, one or more classes may be pre-loaded into a cache prior to receiving a request from an application to load the classes. If an application subsequently requests a class, the request may be satisfied using the class stored in the cache rather than by loading the class at the time the request is received. A probabilistic data structure, such as a Bloom filter, might also be utilized to determine whether a classloader can possibly load a requested class. Only if the classloader can possibly load the requested class will a search be made for the requested class in a classpath associated with the classloader.