The Lean Startup Method: Customer Discovery in Practice
You've read The Lean Startup. You know you're supposed to "get out of the building" and talk to customers. But when you sit down to actually do customer discovery, you hit a wall.
Who exactly should you talk to? How do you find them? What questions do you ask that actually matter?
Here's how to turn Lean Startup theory into a practical customer discovery process that gives you real insights—not just validation bias disguised as research.
Start With Your Riskiest Assumption
Most founders make customer discovery too broad. They want to validate everything at once.
Instead, identify your single riskiest assumption. This is usually one of three things:
- Problem assumption: Do people actually have the problem you think they have?
- Solution assumption: Will your proposed solution actually solve their problem?
- Market assumption: Are enough people willing to pay for this solution?
Pick one. Build your entire first round of interviews around testing that assumption specifically.
For example, if you're building a productivity app for remote workers, your riskiest assumption might be: "Remote workers struggle to stay focused during video calls because of digital distractions."
Find the Right People (The Hard Part)
This is where most founders get stuck. You need to talk to people who actually experience your problem, not just anyone willing to give feedback.
Define your ideal interview participant in painful detail:
- Demographics (age, location, income)
- Behaviors (what tools they use, how they spend their time)
- Psychographics (what frustrates them, what they value)
- Context (when and where they experience your problem)
Then find them where they already gather:
- Reddit communities discussing your problem space
- LinkedIn groups for your target profession
- Industry-specific forums and Slack communities
- Professional associations and meetups
Don't ask friends and family unless they perfectly match your target customer profile. Their feedback is worthless if they're not your market.
Ask Better Questions
Stop asking "Would you use this?" It's a useless question that generates useless answers.
Instead, focus on understanding their current reality:
Problem exploration questions:
- "Walk me through the last time you dealt with [problem]"
- "What's the most frustrating part about [current process]?"
- "How much time/money does this problem cost you?"
- "What have you tried to solve this before?"
Solution validation questions:
- "Show me how you currently handle this"
- "What would need to be true for you to switch from your current solution?"
- "What's the biggest barrier to trying something new here?"
Willingness to pay questions:
- "How much do you currently spend on [category]?"
- "What's this problem worth solving to you?"
- "Who has budget authority for this type of purchase?"
Notice these questions focus on past behavior and current reality, not hypothetical futures.
Run Structured Interview Sessions
Before the interview:
- Prepare 5-7 core questions
- Set up a quiet space and test your recording setup
- Plan for 30-45 minutes maximum
During the interview:
- Start with their background, not your idea
- Ask follow-up questions when they mention pain points
- Let them show you their current tools and processes
- Take detailed notes on exact words they use
After the interview:
- Write up key insights within 24 hours
- Note direct quotes about pain points
- Identify patterns across multiple interviews
- Update your assumptions based on what you learned
Recognize Validation vs. Invalidation
Good customer discovery often invalidates your assumptions. That's not failure—that's success.
Signs you're on the right track:
- People describe the problem in their own words
- They've already tried multiple solutions
- They're willing to spend time/money on the problem
- Multiple people describe similar pain points
Red flags:
- People say "that's interesting" but can't describe when they'd use it
- They haven't tried any existing solutions
- They ask you to explain why they need this
- Conversations feel like you're convincing them they have a problem
Turn Insights Into Action
Customer discovery only matters if it changes what you build.
After 5-10 interviews, look for patterns:
- Problem patterns: What problems do multiple people mention?
- Language patterns: How do they describe their pain points?
- Solution patterns: What do they currently use? What do they wish existed?
- Buying patterns: Who makes decisions? What's their process?
Use these patterns to:
- Refine your target customer definition
- Adjust your value proposition language
- Prioritize which features to build first
- Identify the most compelling positioning
The Most Common Mistake
The biggest customer discovery mistake isn't asking the wrong questions—it's talking to the wrong people.
You can have perfect interview technique, but if you're talking to people who don't actually experience your problem acutely, you'll get misleading data.
Spend more time finding the right participants than perfecting your questions. One conversation with someone who desperately needs your solution is worth ten conversations with people who think it's "nice to have."
What Happens Next
Customer discovery isn't a one-time activity. It's an ongoing conversation that continues throughout your startup journey.
After your first round of interviews, you'll have new assumptions to test. Run another round focused on your next riskiest assumption.
The goal isn't to prove you're right—it's to get closer to building something people actually want.
Your next step: Identify your single riskiest assumption and find three people to interview about it this week.
By the way, we can help with that!