Behavioral question
Tell me about a time you made a mistake
A mistake story is a failure story with a clearer “I caused this.” They want the moment you noticed, the blast radius, and the safeguard. Skip the self-attack. One sentence of ownership is enough.
Check this example, then replace it
The box starts with one STAR answer. Read the scores, then delete it and paste a story from your own work. Scoring stays in the browser.
85/100
Strong
About 54 seconds spoken · 135 words. Spoken time uses 150 words per minute.
Feedback
- This has a clear STAR shape. Only keep numbers you can defend out loud.
Which sentence is which
In February 2024 I shipped a config change that turned off retries for a queue, and jobs started dying during the lunch peak. I was responsible for the config and for the restore. I reverted the change within 12 minutes, wrote a note on the diff that explained the retry field, and added a check that blocks that value in production. I then replayed the 640 dead jobs with the on-call engineer. I added that rejected value to the incident review so the next config change had a named example of what not to ship. The result was the queue drained in 35 minutes, no invoices lost, and the same bad value rejected 4 times the following month by the check instead of by customers. The billing team was the one who felt it.
Why this example holds up
The mistake is one config, not your character. The timestamps (12 minutes, 35 minutes) show you know the incident. The check is the part that makes it a story instead of a confession.
How to answer “Tell me about a time you made a mistake” with STAR
- Situation. Set the scene in one or two sentences: when it was and what was already wrong. For example: In February 2024 I shipped a config change that turned off retries for a queue, and jobs started dying during the lunch peak.
- Task. Say what you personally owned. For example: I was responsible for the config and for the restore.
- Action. Say what you did, in order, with I. For example: I reverted the change within 12 minutes, wrote a note on the diff that explained the retry field, and added a check that blocks that value in production.
- Result. End on the change, with a number you can defend. For example: The result was the queue drained in 35 minutes, no invoices lost, and the same bad value rejected 4 times the following month by the check instead of by customers.
Mistakes on this question
- A humble brag (“I cared too much”) that is not a mistake.
- Spending the whole answer on how bad you felt.
- Fixing it once and leaving the same switch easy to flip.
How to practice it
Say “I caused X” in the second sentence. If you cannot say that sentence, pick a different story.
FAQ
How is a mistake different from a failure?
A failure can be a missed goal you only partly owned. A mistake is a choice you made that was wrong. Either can work. Do not tell the same incident twice.
Should I include a mistake from outside work?
Prefer work. A personal story is harder to check and easier to overshare.