1. A method, comprising: determining, via a processor during de-serialization of a serialized data object, class loader changes from at least one user-defined class loader to a bootstrap class loader; storing, in response to each determined change from the at least one user-defined class loader to the bootstrap class loader, a reference to each user-defined class loader separately from a thread method frame stack, where storing, in response to each determined change from the at least one user-defined class loader to the bootstrap class loader, the reference to each user-defined class loader separately from the thread method frame stack comprises: searching from a top of the thread method frame stack for a first method frame belonging to a latest user-defined class loaded by one of the at least one user-defined class loader; and storing a reference to the one of the at least one user-defined class loader within a latest user-defined class loader (LUDCL) stack; and for each user-defined class load operation of a user-defined class associated with the de-serialization of the serialized data object: identifying a latest user-defined class loader (LUDCL) using the stored reference; and loading the user-defined class using the identified LUDCL.