Walk Through a Project, a Project That Went Wrong, and How You Use AI

Quick Overview

A culture-focused behavioral interview with three questions: describe a project you worked on, describe a project that went wrong, and explain how you use AI tools in your work. It tests clear ownership of decisions, honest reflection on failure, and practical judgment about verifying AI output and respecting its limits.

Walk Through a Project, a Project That Went Wrong, and How You Use AI

Company: Decagon

Role: Software Engineer

Category: Behavioral & Leadership

Difficulty: medium

Interview Round: Onsite

A culture-focused conversation built around three open questions. Answer each one as you would to an interviewer who keeps asking "why" and "what exactly did you do". ### Clarifying Questions - Should the project in the first question be your most impactful one, your most recent one, or one that best shows how you work? - For the failed project, does "went wrong" include projects that shipped late or with problems, or only ones that were cancelled? - Does "how do you use AI" refer to your day-to-day engineering work, to AI features you have built, or both? ### Part 1 — Tell me about a project Walk the interviewer through a project you worked on: what it was for, what you personally did, and how it turned out. ```hint Pick for depth, not size Choose a project where you can explain your own decisions and their trade-offs in detail, even if it was not the largest one you touched. ``` #### What This Part Should Cover - The problem and why it mattered, in terms a non-specialist can follow - Your own role and decisions, clearly separated from the team's work - A result backed by something concrete, such as a metric, a user outcome or a date that was met - What you would do differently now ### Part 2 — Tell me about a project that went wrong Describe a project that did not go as planned: what happened, what part you played in it, and what you did about it. ```hint Own a real share of it Pick a failure where some of the cause was your own decision or omission, and be ready to describe what you changed in your behavior afterwards. ``` #### What This Part Should Cover - What went wrong and the actual impact, stated without minimizing it - Your share of the cause, with no blaming of others - How you responded while it was going wrong, and how it was recovered or closed - A lasting change in how you work, with evidence that you applied it later ### Part 3 — How do you use AI? Explain how you use AI tools in your work today. ```hint Show judgment, not enthusiasm Describe concrete tasks where the tools help you, how you check what they produce, and where you deliberately do not rely on them. ``` #### What This Part Should Cover - Specific, repeatable uses rather than general statements - How you verify AI output before it reaches code review, users or production - Limits you respect, such as confidential data, licensing or tasks where the tools are unreliable - How the tools have changed your speed or quality, with an honest example ### What a Strong Answer Covers - Real stories with specific actions, decisions and results, told in a clear situation-task-action-result order - A consistent picture across all three answers of how you make decisions, collaborate and learn - Honest self-assessment, especially in the failure story - Concise answers that leave room for follow-up questions ### Follow-up Questions - In the first project, what was the hardest technical or people disagreement, and how was it resolved? - In the project that went wrong, when was the first warning sign, and why was it not acted on earlier? - Tell me about a time an AI tool gave you a wrong answer that looked right. How did you catch it? - How would your teammates describe the way you work, and what would they want you to improve?

Overview: A culture-focused behavioral interview with three questions: describe a project you worked on, describe a project that went wrong, and explain how you use AI tools in your work. It tests clear ownership of decisions, honest reflection on failure, and practical judgment about verifying AI output and respecting its limits.

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Decagon
Sep 18, 2026
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A culture-focused conversation built around three open questions. Answer each one as you would to an interviewer who keeps asking "why" and "what exactly did you do".

Clarifying Questions Guidance

  • Should the project in the first question be your most impactful one, your most recent one, or one that best shows how you work?
  • For the failed project, does "went wrong" include projects that shipped late or with problems, or only ones that were cancelled?
  • Does "how do you use AI" refer to your day-to-day engineering work, to AI features you have built, or both?

Part 1 — Tell me about a project

Walk the interviewer through a project you worked on: what it was for, what you personally did, and how it turned out.

What This Part Should Cover Guidance

  • The problem and why it mattered, in terms a non-specialist can follow
  • Your own role and decisions, clearly separated from the team's work
  • A result backed by something concrete, such as a metric, a user outcome or a date that was met
  • What you would do differently now

Part 2 — Tell me about a project that went wrong

Describe a project that did not go as planned: what happened, what part you played in it, and what you did about it.

What This Part Should Cover Guidance

  • What went wrong and the actual impact, stated without minimizing it
  • Your share of the cause, with no blaming of others
  • How you responded while it was going wrong, and how it was recovered or closed
  • A lasting change in how you work, with evidence that you applied it later

Part 3 — How do you use AI?

Explain how you use AI tools in your work today.

What This Part Should Cover Guidance

  • Specific, repeatable uses rather than general statements
  • How you verify AI output before it reaches code review, users or production
  • Limits you respect, such as confidential data, licensing or tasks where the tools are unreliable
  • How the tools have changed your speed or quality, with an honest example

What a Strong Answer Covers Guidance

  • Real stories with specific actions, decisions and results, told in a clear situation-task-action-result order
  • A consistent picture across all three answers of how you make decisions, collaborate and learn
  • Honest self-assessment, especially in the failure story
  • Concise answers that leave room for follow-up questions

Follow-up Questions Guidance

  • In the first project, what was the hardest technical or people disagreement, and how was it resolved?
  • In the project that went wrong, when was the first warning sign, and why was it not acted on earlier?
  • Tell me about a time an AI tool gave you a wrong answer that looked right. How did you catch it?
  • How would your teammates describe the way you work, and what would they want you to improve?
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