A breaking schema change has been filed: the users table renames signup_date to created_at and chang
A medium Pipeline Design mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Pipeline Design
- Difficulty
- medium
Interview Prompt
A breaking schema change has been filed: the users table renames signup_date to created_at and changes its type from DATE to TIMESTAMP. Twelve downstream consumer teams read this column. A flag-day deploy is impossible. The section's pattern is expand-contract in four phases: expand (add new shape, keep old), dual-write (populate both for every event), migrate (cut consumers over to new shape one at a time), and contract (drop old shape after every consumer has migrated). Order the phases on the canvas by adding four phase-marker nodes between the producer and the consumers, named so each marker states which phase it represents and what the producer and consumers are doing at that phase.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your pipeline design solution with real code execution
- Get instant feedback and a hire/no-hire decision