During June 2025, Jonas Norlinder delivered a foundational refactor to the JetBrainsRuntime repository, focusing on garbage collection and virtual machine operations in C++. He introduced a new hierarchy for GC-related VM operations by creating base classes, VM_Heap_Sync_Operation and VM_GC_Collect_Operation, and implemented the is_gc_operation() method to improve categorization and handling of these operations. This architectural change enhances code maintainability and sets the stage for future improvements in garbage collection. Jonas applied his expertise in code refactoring, garbage collection, and VM operations, producing a well-structured solution that addresses long-term maintainability without introducing new bugs during this period.