How long should a customer discovery interview be?

Block 30 minutes for a customer discovery interview. This is enough time to cover key questions without losing focus. Some interviews will run longer if the conversation is valuable, but 30 minutes is a good default.

What are common mistakes in customer interviews?

Common mistakes include: pitching instead of learning, asking leading questions, asking yes/no questions without follow-ups, asking about future behavior instead of past behavior, talking too much (aim for the customer to talk 90% of the time), ignoring negative reactions, interviewing the wrong people, conducting group interviews, and not synthesizing learnings afterward.

Running the Interview

Good interviews take prep, listening, and follow-up. The real insights come from patterns across many conversations — not from any single one.

Before the Interview

Make an outline, not a script

Have 5-7 key questions ready, but be ready to go off-script when something interesting comes up. Rigid scripts miss the good stuff.

Record everything

Ask if you can record the call. Use video, audio, and a transcript. Have someone take notes or do it yourself right after.

Block 30 minutes, no distractions

Close other tabs. Silence your phone. Give them your full attention.

During the Interview

Listen more. Talk less.

→

Don't pitch. Focus on their world, not yours.

→

Get them to tell stories. "Tell me about the last time you…" beats any opinion question.

→

Dig in. Ask why. Then ask why again. The good stuff is two or three levels down.

→

Repeat back what you heard. "So what I'm hearing is…" — it often surfaces more.

→

Let them talk ~90% of the time. Watch for frustration and hacks — that's where the real pain is.

→

Skip hypotheticals. Ask what they do now, not what they'd do someday.

After the Interview

Insights come from patterns across calls.

→

Write down takeaways right away. Don't wait until tomorrow. Capture it while it's fresh.

→

Say thanks. Keep them updated. Early interviewees often become early customers.

→

Share notes with your team. Name, date, interviewer, and what you learned.

→

Look across interviews. What keeps coming up? What doesn't? Pay attention to what contradicts your idea.

→

Update what you believe. Decide what to test next based on what you learned.

If You're Showing a Prototype

If you want to show something you've built, remember: people can't give useful feedback until they understand what it does.

Let them use it first. Walk them through it. Only after they get it can you ask if it solves their problem.

First make sure they understand it. Then ask if it's valuable.

Common Mistakes

×Pitching instead of learning

×Leading questions

×Yes/no questions without follow-ups

×Asking about future behavior

×Talking too much

×Ignoring negative reactions

×Interviewing the wrong people

×Group interviews

×Not synthesizing learnings

Key Takeaway

Outline, don't script. Let them talk 90% of the time. Write down insights right after. Look for patterns across calls — not conclusions from a single conversation.