During February 2025, Dan focused on enhancing scheduler correctness in the htcondor/htcondor repository by addressing a complex concurrency bug. He identified and resolved issues in concurrency limits evaluation, claim recycling, and the handling of partitionable slot leftovers, which previously led to incorrect claim reuse and inaccurate resource accounting. Using C++ and leveraging his expertise in concurrency control and system programming, Dan’s fix improved scheduler stability and predictability under high-concurrency workloads. His targeted changes ensured that leftover partitionable slots are properly managed, reducing the risk of mis-scheduling and contributing to more reliable throughput in demanding cluster environments.