# A global trading platform consolidates the lesson into one architecture Canonical URL: Domain: Pipeline Design ยท Difficulty: medium ## Problem A global trading platform consolidates the lesson into one architecture. Three event sources (mobile retail trades, institutional order flow, market-data feed) write to a shared Iceberg target. Schema changes flow through a registry on the producer side and a CDC allow-additive policy on the database side. The streaming pipeline serves real-time desks; a daily reconciliation pass serves audit consumers; a delta log quantifies the gap. Each source has a profile-matched watermark strategy. The schema-quarantine topic catches blocked destructive changes for human decision. Compose the system: schema registry between producers and topics with compatibility named; per-source watermark transforms named for their strategy and parameters; aggregation with event_time, lateness budget, dead-letter; CDC allow-additive policy with quarantine destination; reconciliation pass with daily cadence and atomic partition overwrite; delta-metric log; both real-time and audit consumers reading the shared Iceberg target. ## Related - [All practice problems](https://datadriven.io/problems) - [Mock interview mode](https://datadriven.io/interview/a-global-trading-platform-consolidates-the-lesson-into-one-a-f18ab304) - [System Design Interview Questions](https://datadriven.io/data-engineering-system-design) - [Data Engineering Interview Prep Guide](https://datadriven.io/data-engineer-interview-prep) - [Daily Challenge](https://datadriven.io/daily) --- Source: DataDriven (https://datadriven.io). 100% free data engineering interview prep. Live code execution against Postgres 16, Python 3.11, and Spark sandboxes. No paywall, no premium tier, no signup gate.