Phase 11 — Issue Journey Level 5: PMC
Summary
PMC-level engineering challenges. Where earlier phases focused on implementing fixes, this phase focuses on the decisions that govern how Apache projects evolve — API deprecation lifecycles, storage format migration planning, and building consensus across a distributed group of engineers who cannot be overruled by any single person.
Labs
| Lab | Title | Core Skill |
|---|---|---|
| 01 | Deprecated API Migration Analyzer | Classify call sites against a deprecation timeline; determine migration urgency |
| 02 | Storage Format Migration Planner | Plan multi-step table format migrations; evaluate capability deltas and rollback safety |
| 03 | Consensus Tracker | Model lazy consensus, explicit approval, and blocking objection in an ASF design thread |
Apache Project Context
| Lab | Real-world reference |
|---|---|
| 01 | Spark RDD API vs. Dataset API evolution; SPARK-28 series deprecation notices |
| 02 | Hive ALTER TABLE … STORED AS format migrations; migration from Text → ORC → Parquet |
| 03 | ASF design proposals on dev@ lists; lazy consensus rules (72-hour minimum window) |
What PMC Members Actually Decide
PMC members don't only merge code — they make binding decisions on questions that affect every downstream user for years:
- When is an API stable enough to deprecate without a migration path?
- Can a storage format change be rolled back if performance regresses?
- Is a design proposal safe to ship when half the PMC hasn't responded?
These labs build the reasoning patterns behind those decisions.
Interview Relevance
At Staff/Principal level, interviewers expect you to describe decisions where you had to build consensus across people you did not manage, navigate a deprecation that broke existing users, or design a system migration that had to be online and reversible. These three labs give you concrete examples.