How many customer interviews do I need before I trust the job I've found is real?
The short answer
There's no magic number, but the honest signal is repetition: when your last three interviews stop surprising you and start confirming the same struggle, you're close. Most founders stop at five when the real jobs surface around interview ten to fifteen, because the early ones teach you how to ask better. As a starting point, keep going until a new interview no longer changes your mental model of the job.
Go deeper, your way
3 hand-picked resources, 3 link-checked. Pick how you want to dig in.
▶️ Video
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Why we picked it
Reading about the switch interview is one thing, watching one run live is another. Bob Moesta and Chris Spiek interview an audience member on the spot about a real purchase, reconstructing the timeline of struggle from first thought to buy and mapping the forces that pushed and pulled them. It is the most concrete way to learn the actual questioning technique for uncovering the real job.
Why we picked it
The single best thing ever written on customer conversations. It teaches you to ask about the customer's life and past behaviour, not your idea, so you can't be lied to. If a founder reads one thing before talking to a single customer, it's this.
Why we picked it
The honest answer to 'how many' is not a magic number, it is saturation: you keep going until new interviews stop teaching you anything new. This piece explains that idea plainly and gives a workable starting point (begin with about 5 to 6, then continue until the themes stop shifting), which is exactly the judgment call a founder is trying to make. Treat it as a rule of thumb to sanity-check your gut, not a quota to hit.
Saturation is the real stopping rule: when the same jobs and pains keep repeating and fresh interviews add nothing, you can trust the pattern.
Start small (roughly 5 to 6) for a focused, similar group, and add more the moment answers start diverging.
The number depends on how varied your customers are and how broad your question is, so a wildly mixed audience needs more conversations than a narrow one.
