The AWS Certified Data Engineer – Associate (DEA-C01) exam covers four content domains, and they’re not weighted equally. Here’s exactly what’s tested and where to spend your study time.

The four domains and their weight

Data Ingestion and Transformation — 34%. The biggest domain by far: Glue ETL jobs and crawlers, Kinesis Data Streams and Firehose, DMS, Spark on EMR, and batch vs streaming patterns.
Data Store Management — 26%. S3 as a data lake, Redshift, DynamoDB, RDS/Aurora, partitioning, and data formats like Parquet and ORC.
Data Operations and Support — 22%. Orchestration, monitoring, and troubleshooting pipelines.
Data Security and Governance — 18%. Encryption, access control, and Lake Formation.

Where to focus

Domain 1 alone is over a third of the exam, so master Glue and Kinesis first — they show up constantly. Domain 2’s partitioning and file-format questions (Parquet over CSV to cut scan cost) are reliable points too.