C2W4 Practice Lab 1 – DAG Not Appearing in UI After S3 Sync

Course Q&A Data Engineering Source Systems, Data Ingestion, and Pipelines
1

I’ve successfully uploaded my DAG file (user_sessions.py) to the S3 bucket using:

bash

aws s3 sync src s3://de-c2w4lab1-458900736587-us-east-1-dags/dags

  • First sync shows: upload: src/user_sessions.py …

  • Second sync shows no output (expected – files are in sync)

  • Confirmed file exists in S3:

    bash

    aws s3 ls s3://de-c2w4lab1-458900736587-us-east-1-dags/dags/user_sessions.py

    → Returns correct timestamp and size

2025-11-04 10:26:18 15986 user_sessions.py

But in the Airflow UI, no DAGs appear at all – the list is completely empty.