# An ad-tech company has three storage problems on one platform: a bidding service writing 80,000 tran Canonical URL: Domain: Pipeline Design ยท Difficulty: medium ## Problem An ad-tech company has three storage problems on one platform: a bidding service writing 80,000 transactions per second with 12ms primary-key lookups, a reporting team scanning 365 days of bid_facts (2 PB raw) for an advertiser dashboard, and a data science team training on the full raw bid history. Apply the entire L3 storage tier (the three foundational shapes plus the four optimization levers) so each workload runs on storage matched to its access pattern. ## Related - [All practice problems](https://datadriven.io/problems) - [Mock interview mode](https://datadriven.io/interview/an-ad-tech-company-has-three-storage-problems-on-one-platfor-3fcf14d3) - [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.