HaaLeo worked on the aws/aws-sam-cli repository, focusing on backend and API development using Python. During the month, HaaLeo addressed a timing accuracy issue by implementing millisecond-precision event timestamps for API Gateway events. This was achieved by leveraging Python’s time_ns() function and converting the result to milliseconds, ensuring more accurate requestTimeEpoch values. The fix improved the reliability of timing data, which is critical for downstream analytics and billing systems that depend on precise event information. Although the work centered on a single bug fix, it demonstrated careful attention to detail and a solid understanding of backend data integrity requirements.