System Design — Apache Ecosystem Walkthroughs

Three full design walkthroughs at the altitude expected of a staff/principal candidate or a PMC-level design-doc author. Each follows the same discipline the Phase 12 design-doc capstone requires: problem → constraints → alternatives with rejection reasons → chosen design → failure modes → rollout/compatibility plan.

DocDesign problemTrains
01-yarn-scheduler-design.mdMulti-tenant cluster scheduler (YARN-style)Resource arbitration, preemption, fairness vs utilization
02-hive-metastore-scaling.mdScaling a metadata service from thousands to millions of partitionsHot metadata stores, caching, API-compatibility under load
03-public-api-evolution.mdEvolving a public API used by thousands of downstream projectsDeprecation lifecycle, binary vs source compat, migration tooling

How to use these

  1. Before reading each doc, spend 45 minutes designing it yourself on paper from the problem statement at the top. Then compare — the deltas are your study list.
  2. In interviews, the differentiator is not the final architecture but the order you surface concerns: workload characterization → consistency/compat constraints → the 2–3 real alternatives → failure modes — before drawing boxes.
  3. Each doc ends with interviewer follow-up questions. Practice answering them aloud.