Mark Shannon presented Python's garbage collection challenges at the 2026 Language Summit, discussing why the incremental garbage collector shipped in Python 3.14 was reverted to the generational approach from 3.13 due to memory pressure issues. The incremental collector reduced pause times from ~3 seconds to tens of milliseconds but had poor scavenge effectiveness (~1%) and negative memory implications, while the generational collector offers better memory usage despite lower pause time performance.