IT Career Guides & Free Resources
Expert roadmaps, tutorials, salary guides and interview prep across Data Science, Generative AI, Python, Cloud & Analytics — written by GloryTecks trainers in Hyderabad.
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ETL vs ELT: Differences and When to Use Each
The difference between ETL and ELT, shown by running both on three million real taxi trips: ETL stores 31 transformed rows while ELT keeps every raw row and transforms in SQL, then a business rule changes and only ELT can re-derive without re-extracting; plus when to choose each, reverse ETL and streaming.
Building an ETL Pipeline with ADF Step by Step
A first ADF pipeline copies data from A to B. A production ETL pipeline must also survive reruns, updated records and broken extracts. This step-by-step guide builds the stage, validate and merge design, shows on real runs why plain appends go wrong, and gives the ADF pipeline and stored procedure.
ETL Interview Questions for Data Engineers
ETL interviews test what happens when real extracts misbehave. Six questions are answered on the two yearly files of a real online retailer, which overlap by nine days: what a plain append does, how a watermark should compare, why there is no key, which quality rules need business input, and how to prove a load.
Building an ETL Pipeline on AWS Step by Step
A step-by-step ETL pipeline on AWS, run end to end: extract raw files from S3, validate 2.96 million real rows with named rules, load cleaned Parquet into a partition, register it in the Glue Data Catalog, write a reconciliation report, and rerun without duplicates. Each step is mapped to its production service.