What SQL topics are essential for data engineering interviews?

Window functions, CTEs, complex joins, aggregations with edges – all tied to business problems.

How do I prepare for data engineering system design?

Practice sketching scalable pipelines: ingestion to serving, with trade-offs on batch/streaming/reliability.

Rarely – focus on data processing, cleaning, transformation over algorithms.

You've aced LeetCode, but data engineering interviews still crush you. Here's why – and the cynical fix from a vet who's seen it all.

theAIcatchup Apr 10, 2026 3 min read

Focus 60% on advanced SQL for real business problems, not rote queries. 𝕏
Pipeline design and system reliability beat Python tricks every time. 𝕏
Storytell projects with impact metrics – interviewers buy results, not resumes. 𝕏

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Originally reported by Dev.to