**Situation**: Ingestion job exceeds SLA; need to find and fix bottleneck.
**Task**: Systematically isolate slow stage (source, transfer, or Spark).
**Action**: (1) **Add timestamps**—log start/end per stage; identify largest delta. (2) **Spark UI**—Jobs/Stages: which stage dominates? Task duration histogram shows skew. (3) **Source checks**—DB: connection pool exhaustion? Network latency? Lock contention? (4) **Sqoop/Kafka**—Sqoop: `--num-mappers`, `--fetch-size`, `--split-by`....
The complete answer continues with detailed implementation patterns, architectural trade-offs, and production-grade considerations. It covers performance optimization strategies, common pitfalls to avoid, and real-world examples from companies like Swiggy. The answer also includes follow-up discussion points that interviewers commonly explore.
Continue Reading the Full Answer
Unlock the complete expert answer with code examples, trade-offs, and pro tips - plus 1,863+ more.
Or upgrade to Platform Pro - $39
Engineers who used these answers got offers at
AmazonDatabricksSnowflakeGoogleMeta
According to DataEngPrep.tech, this is one of the most frequently asked Spark/Big Data interview questions, reported at 1 company. DataEngPrep.tech maintains a curated database of 1,863+ real data engineering interview questions across 7 categories, verified by industry professionals.