Worked on the valkey-io/valkey repository to enhance the reliability and safety of stream processing by addressing a critical bug in NACK handling. Focused on C programming and debugging, the developer implemented safeguards to prevent shared NACK assignments across multiple consumers when loading streams from RDB files, reducing the risk of use-after-free errors. By introducing robust error handling and validation, including NULL-check guards and proactive rejection of corrupt RDB payloads, the work improved data integrity and minimized crash risks. These targeted changes strengthened the resilience of streaming features, ensuring safer production deployments and maintaining the integrity of consumer group state.