Worked on the volcengine/verl repository to enhance deployment reliability by addressing a concurrency issue in the SGLang rollout. Focused on backend development using Python, the work involved fixing a port allocation race condition that previously allowed multiple processes to contend for the same port under heavy load. By ensuring unique port assignment per rank ID, the solution improved rollout stability and prevented service interruptions in distributed systems environments. The changes were carefully aligned with the release process and prepared for documentation, demonstrating a methodical approach to concurrency handling and system robustness within a production-grade distributed backend infrastructure over the course of the month.