# Tell me about a time you solved a difficult problem at work

Choose a problem where the cause wasn't obvious, then walk the interviewer through your thinking: what you noticed, what you suspected first, how you tested it, what you ruled out, and the fix that worked. End with the result and what you changed so it wouldn't happen again. The reasoning is the answer; the fix is only the last line.

By the Speaking Coach team at Sodhera Intelligence. Updated 2026-10-22. Source: https://www.orecci.com/speaking-coach/interview-questions/tell-me-about-a-time-you-solved-a-problem/

## Why the reasoning matters more than the fix

Most people answer this question with the ending: "The reports were wrong, so I fixed the formula." That tells the interviewer you can fix a formula. It doesn't tell them how you'll handle the next problem, which will be different.

What they are really testing is your method. Can you:

- **Notice** that something is wrong before it gets worse?
- **Form a guess** about the cause instead of trying random fixes?
- **Test** that guess cheaply, and change your mind when the evidence says so?
- **Fix the cause**, not only the symptom, and stop it coming back?

So the middle of your answer, the part most people skip, is where the marks are.

## Fix-only answers versus reasoning answers

| Fix-only answer | Reasoning answer |
| --- | --- |
| "Customers were complaining, so I updated the FAQ." | "Complaints doubled in a week. I sorted 60 tickets by topic and saw 40 were about one new shipping rule, so I knew it wasn't a general service issue." |
| "The machine kept jamming, so I called maintenance." | "It only jammed on the night shift. That ruled out the part itself, so I compared settings between shifts and found the night crew used a different label roll." |
| "I rewrote the code and it worked." | "My first guess was the database. I checked query times and they were normal, so I moved on to the network calls, and that's where the delay was." |

Notice the words that carry the reasoning: *so I knew*, *that ruled out*, *my first guess was*, *I checked*. Use them out loud.

## A five-step structure

This follows the [STAR method](/speaking-coach/guides/star-method/), with the Action split into the steps of your thinking.

1. **The problem and why it mattered.** One or two sentences with the cost: money, time, customers, risk.
2. **What you noticed.** The clue that started your thinking.
3. **What you tested and ruled out.** One or two wrong guesses are good. They show you checked instead of assuming.
4. **The fix.** What you changed, and who you brought in.
5. **The result and the safeguard.** A number if you have a real one, plus what you put in place so it wouldn't recur.

Aim for 75–90 seconds. That's a little longer than most answers, because the steps need room, but don't let it become a technical lecture. If the interviewer wants more detail, they will ask.

## Example answers

These are made-up examples to show the structure. Use your own problem.

### Accounts (finance assistant)

> "Our monthly bank reconciliation was off by a few hundred pounds three months in a row, and the team had started writing it off as 'timing'. It mattered because auditors were due. I noticed the gap was always a round-ish number, which suggested a recurring payment, not random errors. I pulled every transaction in that range and found nothing missing. So I checked the other direction: something on our side that wasn't in the bank. That's where it was. A cancelled supplier contract was still set up as a standing payment in our system but had been stopped at the bank. I removed it, corrected the three months, and added a step to our offboarding checklist for suppliers. The next reconciliation balanced to the penny."

### Customer support

> "Refund requests jumped by about a third in two weeks, and my manager asked me to find out why. I read through 80 tickets and tagged each one. Most were about late deliveries, but only for one region. My first guess was the courier. I checked their tracking data and they were on time. Then I looked at when orders were placed: the late ones were all placed after 2 p.m. on Fridays, which our new warehouse rota didn't cover. I showed the pattern to operations with five example orders, they added a Friday afternoon shift, and refund requests went back to normal within a month."

### Software (junior developer)

> "Our app's login page was timing out for some users but never for us in testing. I first suspected server load, but the slow logins happened at quiet times too. I asked support for the affected accounts and noticed they all had very old accounts with long histories. That pointed to the data, not the server. One query was loading the whole history on login. I changed it to load only the last 30 days, added a test with a large account, and the timeouts stopped. I also added that large test account to our standard test set."

### Graduate or student

> "In a group engineering project, our prototype's sensor readings drifted every afternoon. Two teammates wanted to replace the sensor. Before spending the budget, I logged readings every ten minutes for two days next to a thermometer. The drift tracked the room temperature, which rose when the sun hit the lab window. We moved the rig and added a simple temperature correction. It saved us the cost of a new sensor and became a section of our final report."

## Phrases that show your thinking

When you practice, check that your answer includes at least two of these:

- "The first thing I noticed was…"
- "My first guess was… so I checked… and it wasn't that."
- "That ruled out…"
- "The pattern pointed to…"
- "To make sure it wouldn't happen again, I…"

If you tend to get lost in the middle, the guide on [how to stop rambling](/speaking-coach/guides/how-to-stop-rambling/) has a simple way to keep each step to one or two sentences.

## Mistakes to avoid

| Mistake | Why it hurts | Instead |
| --- | --- | --- |
| A problem someone else solved | Follow-up questions will expose it | Pick a smaller problem you owned |
| Too much jargon | A non-specialist interviewer can't follow your logic | Explain each step as you would to a smart friend |
| No wrong guesses | It sounds as if you got lucky | Mention one thing you ruled out |
| Ending at the fix | It misses the result and the safeguard | Add the outcome and what you changed for next time |

## Questions people ask

### Does the problem have to be big?

No. A modest problem told with clear reasoning beats a dramatic one told vaguely. Pick something where the cause wasn't obvious at first.

### What if the problem was partly my own fault?

That can work well if you own it in one sentence and spend the rest on how you found and fixed it. If the main story is your error, use it for [a question about a mistake](/speaking-coach/interview-questions/tell-me-about-a-time-you-made-a-mistake/) instead.

### Should I include technical detail?

Enough to show the logic, no more. Name the tool or system in plain words and explain why each check mattered. Save deeper detail for follow-up questions.

### How is this different from 'Tell me about a challenge you faced'?

A [challenge](/speaking-coach/interview-questions/tell-me-about-a-time-you-faced-a-challenge/) can be about pressure, workload or people. A problem-solving question wants to see you work out a cause. Choose a story with a puzzle in it.

### What if I can't remember the exact numbers?

Use honest approximations like "about a third" or "a few hundred pounds". Don't invent precise figures you can't back up if asked.

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