Sandro Xu

Built 4 Airflow DAGs to ingest operational and reporting extracts from multiple client source systems into Snowflake, including schema validation and Slack failure alerts; backfilled 6 months of historical data. Added 15 dbt tests (not_null, unique, relationships) and column-level documentation to 20+ existing models in the reporting mart. Investigated a recurring late-arriving-data bug in a PySpark job on AWS Glue; identified a timezone mismatch in the partition filter and submitted the fix in a mentor-reviewed PR.

Data Engineer Intern - Allegiant Technologies - Remote

(2026-02 - 2026-05)

• Built 4 Airflow DAGs to ingest operational and reporting extracts from multiple client source systems into Snowflake, including schema validation and Slack failure alerts; backfilled 6 months of historical data.
• Added 15 dbt tests (not_null, unique, relationships) and column-level documentation to 20+ existing models in the reporting mart.
• Investigated a recurring late-arriving-data bug in a PySpark job on AWS Glue; identified a timezone mismatch in the partition filter and submitted the fix in a mentor-reviewed PR.
• Wrote ad-hoc SQL for service-usage and SLA reporting, one query promoted into a recurring Power BI dashboard; authored the team's dbt + Snowflake onboarding doc.

Graduate Research Assistant - Cornell University - Ithaca, NY

(2024-09 - 2025-09)

• Built Python pipelines to process geospatial emissions data across 36 US cities and 900 coordinate grid points from NetCDF satellite datasets; applied statistical tests (KS, Anderson–Darling, correlation) to identify patterns across 7 emission sectors.

Master of Engineering - Systems Engineering - Cornell University (2024-08 - 2026-01)

Bachelor of Science - Statistics - University of British Columbia (2019-09 - 2024-05)