Mock interview questions
Rehearse coding and behavioral answers, then follow the technical mock rounds.
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Explain your most difficult project.
A difficult-project answer should focus on one concrete challenge and how you handled it. The interviewer is assessing problem solving, ownership and learning more than the project's impressive name. Use real constraints and evidence so the explanation remains defensible under follow-up questions.
Tell me about a production issue.
A production-incident answer explains impact, investigation, mitigation and prevention in a clear order. It should show that you worked from evidence and reduced risk while users were affected. Use a genuine incident and avoid claiming a root cause you never confirmed.
Tell me about a technical disagreement.
A technical-disagreement answer shows how you compared competing priorities and reached a workable decision with others. The goal is to explain reasoning and collaboration, not prove that you won an argument. Use an example where evidence, constraints or a small experiment helped the team choose.
Tell me about a decision you changed later.
Changing a technical decision can show good judgment when new evidence invalidates an earlier assumption. Explain why the original choice was reasonable at the time and what information changed. Then describe how you migrated safely rather than simply declaring the first choice bad.
How do you validate AI-generated code?
Validating AI-generated code means taking responsibility for its behavior rather than accepting plausible-looking output. Start from requirements and trace the important paths, then use tests and documentation to verify assumptions. Generated code deserves the same correctness, security and maintainability standards as manually written code.
How do you maintain code quality?
Code quality is the ability of a codebase to remain correct, understandable and safe to change. It comes from clear design, meaningful tests, review and feedback from production behavior. Tools enforce some consistency, but they do not replace sound business rules or ownership of dependencies.
How do you remove duplicate IDs from an array?
Deduplication removes repeated values according to a defined equality rule. JavaScript Set handles primitive IDs conveniently and keeps the order of first insertion. Objects are compared by reference, so deduplicating records by an id field requires an explicit key-based approach.
Difficulty is an editorial estimate. Completion means you chose to mark a question as understood.