Got a message from an Apple recruiter on LinkedIn and things moved quickly. First was the usual HR screen - basic intro, project highlights, etc. Then a manager round focused mostly on past work and a few behavioral questions around missed deadlines and long-term projects. Next was a technical phone round - 1 hour, covered Python basics, ETL, and a solid chunk of SQL (joins, window functions, pivots). Some quick-fire questions on Redshift vs Postgres, Parquet vs CSV, and Spark vs MapReduce. Had to write a function for binary tree traversal and optimize median-finding for large lists. Final was a full-day virtual onsite - 4 rounds: coding, DB design, data modeling, and a round with a senior team member. SQL-heavy again, with tasks like schema design, complex queries, and even a mock market basket analysis. Also dove into how I’d structure end-to-end data pipelines. I leaned on LC, Grokking, and did a couple of mocks on Prepfully - super useful, especially for the SQL and design bits. Got the offer!

Explain the concept of monkey patching with the help of an example.