A computer comprising processors and memory may implement an application execution engine to execute an application including both managed code and unmanaged code, the managed code providing memory safety for accesses to objects in memory and the unmanaged code providing no such safety. Responsive to a request from managed code, the application execution engine allocates memory for an object in a managed pool and the object is accessible to managed code in a managed state. Responsive to a requirement for unmanaged code to access the managed object, the application execution engine transforms the object to be accessible in an unmanaged state, the transformation including allocating memory for the object in an unmanaged pool, copying data from managed memory to unmanaged memory according to a predetermined unmanaged layout, releasing the managed memory and using an address of the unmanaged memory to access the object in the unmanaged state.