Worked on enhancing unnesting performance in the spiceai/datafusion repository, focusing on optimizing data processing workflows using Rust. Addressed a performance bottleneck by eliminating redundant data copying in the unnest operation and introduced a repeat mask mechanism to distinguish between repeated and null-filled columns. Expanded the test suite to cover a broader range of scenarios, ensuring correctness and preventing regressions. The approach emphasized performance optimization and correctness, reducing CPU and memory overhead for unnest-heavy workloads. All changes were aligned with related pull requests and documentation, supporting traceability and repeatability. The work demonstrated depth in Rust and data processing techniques.