"Tell me about a time you disagreed with a peer’s technical design. What was the disagreement, how did you handle it, and what was the outcome? If the final decision went against your view, explain how you supported it afterward."
For a Data Engineer at Meta, design disagreements often happen across ingestion pipelines, data models, backfills, and downstream consumer expectations in systems like Hive, Presto, Spark, Airflow, and internal datasets that feed product analytics. This question tests whether you can influence without authority, challenge ideas without making it personal, and keep execution moving when the answer is not obvious. Interviewers want to see how you balance technical judgment, speed, reliability, and partnership with another engineer who is operating at your level.
They are also looking for signs that you can work through ambiguity: maybe both designs had trade-offs, the requirements were incomplete, or multiple teams depended on the outcome.
A strong answer uses one specific disagreement with real stakes, shows how you understood the other engineer’s reasoning, and explains the data or principles you used to evaluate options. The best responses are structured in STAR format, include a clear result, and show maturity: either you changed the decision with evidence, or you disagreed and committed once the team aligned.