In the blog post, the author explores the innovative data structure used by Zed, a high-performance code editor, focusing on its implementation of a "rope" through a SumTree. The rope, a type of binary tree, offers significant advantages over traditional strings for text representation, particularly in large files, due to its efficiency in handling text modifications without reallocating large continuous memory blocks. Zed's rope is not a classic binary-tree but a SumTree, which allows for concurrent access, snapshots, and asynchronous operations, aligning with Zed's goals for high performance and flexibility. The SumTree, a thread-safe, copy-on-write B+ tree, facilitates complex text operations such as converting between UTF8 and UTF16 rows/columns in O(log N) time. This structure enables efficient handling of text edits by updating tree pointers rather than moving large memory blocks, making it ideal for Zed’s requirements. Additionally, the SumTree is utilized throughout Zed, powering various components beyond the rope, demonstrating its integral role in Zed's architecture.