Varun Bansal worked on backend performance optimization for the wazuh/wazuh-indexer repository, focusing on improving index merge throughput under heavy load. He introduced a dynamic global maxMergeAtOnce setting, increasing the default from 10 to 30, which enabled more parallel segment merging and reduced index merge latency. The implementation involved updating core index service configuration to support runtime adjustments without redeployment, along with comprehensive integration tests and changelog documentation. Using Java and leveraging his skills in performance tuning and system configuration, Varun ensured all changes were validated in CI and merged to main, delivering measurable improvements in data availability and search performance.