Strong SQL + PySpark with a production-first mindset; real-time card-transaction pipeline design with duplicate handling.
Cloud / platform
Hybrid; Hadoop/Hive/Spark heavy, GCP/AWS in places
Reported difficulty
Not reported
Composite: recruiter → SQL (2nd-highest-salary-per-dept; window) → PySpark (skew optimization; repartition vs coalesce) → system design (real-time card-transaction pipeline with dedup) → behavioral (production incident ownership).
Answered questions on what American Express actually asks — each with the short answer, the answer that gets you rejected, and the follow-up.
Then build one and have it reviewed: design a daily orders pipeline or model a marketplace. No account.