Worked on optimizing data access and reliability across the opendatahub-io/feast and feast-dev/feast repositories, focusing on backend development and data engineering with Python, AWS, and BigQuery. Introduced a type-safe ProjectionExpression for DynamoDB, reducing data transfer and latency by retrieving only requested features. Addressed array handling in BigQuery by enabling correct list inference during Parquet loads, ensuring data integrity for array columns. Enhanced protocol buffer compatibility by adding regression tests for protobuf 7.34, verifying double precision round-trips without relying on MessageToDict. Emphasized robust type checking and unit testing to maintain reliability and prevent regressions in critical data workflows.