In January 2025, Andrey Mikhailov enhanced the resiliency of the jj indexing API in the pksunkara/jj repository by refactoring the Index trait and its implementations to return Result types instead of directly returning Vec<CommitId>. This Rust-based change introduced robust error handling, replacing production unwraps and reducing the risk of crashes in data pipeline jobs. By leveraging error handling techniques and version control systems, Andrey improved error propagation and observability across indexing operations. The update increased production safety and reliability, ensuring that downstream systems could better handle failures and maintain operational stability without introducing new features during the period.