A historical Google hiring practice requiring PM applicants to demonstrate they had proactively learned at least two different, unrelated parts of the business (e.g., marketing and analytics) before applying.
The heuristic isn't really testing domain knowledge in either area — it's using self-directed learning across two unfamiliar domains as a proxy for the candidate's ability to independently learn the rest of the business once hired. It's a specific, testable instance of Business Acumen as Curiosity, Not Credentials, and functions as an informal filter alongside more structured tools like the MSN List (Must/Should/Nice-to-Have Hiring Framework). Connects to Google's Engineering-Led, User-Focused Era (Historical Case Study) as a period-specific practice.