Worked on the jeejeelee/vllm repository to improve backend reliability and configuration management over a two-month period. Addressed environment-variable handling by registering VLLM_BATCH_INVARIANT in the configuration, which reduced unknown variable warnings and improved CI stability. Enhanced test coverage to ensure consistent batch invariance across environments, supporting more predictable runtime behavior. In the video processing pipeline, fixed a PyAV backend bug that mislabeled keyframes, adding regression tests to prevent future decoding errors. Focused on Python-based backend development, environment configuration, and testing, with an emphasis on correctness and reliability for multimodal AI workloads and production-ready video frame retrieval.