March 2026 focused on correctness and reliability of the cost-based optimizer (CBO) in ytsaurus/ytsaurus. Key deliverable was a bug fix to the interesting orderings finite-state machine used by SQL plan generation, making the handling order-sensitive so that the actual key order is respected during shuffles. This eliminates a correctness gap where the same shuffle could be reused with reversed key orders, which could produce incorrect results in distributed executions. The change was implemented in commit 216ca6acb62e3f3a416e9c0770118dea7c636296 and is tracked in GitHub PR 35609, with a changelog entry recorded (commit 2d8e98048cb669bfc7048a227a8b42504664a273).

November 2025: Delivered configurable Shuffle Elimination cutoff for the cost-based optimizer (CBO) benchmarking across two major repositories, enabling more nuanced tuning of query plans based on join counts. Implemented a flexible cutoff parameter in ydb-platform/ydb and ytsaurus/ytsaurus, with corresponding commit-level refinements and alignment with upcoming external PRs (notably ydb-platform/ydb PR 27065). No explicit bug fixes documented in this period; primary focus was feature delivery, benchmarking readiness, and cross-repo coordination.