How to Run Customer Interviews When You Have a Full-Time Job

Everyone agrees you should talk to customers before you build. Almost nobody explains how to do it when your calendar belongs to someone else between 9 and 6, and the people you need to speak to are working exactly the same hours.

This is the logistics problem, not the theory. The theory is covered well elsewhere. What follows is how to actually get fifteen conversations done in six weeks without taking leave or telling your employer.

Accept the constraint instead of fighting it

You have roughly four usable slots a week: early morning before work, two lunch breaks, weekday evenings after 8, and Saturday morning. That is enough for three conversations a week, which is enough for fifteen in five weeks.

The mistake is trying to run this like a full-time founder would, with midday calls and same-week rescheduling. You cannot, so build a process that assumes you cannot.

Ask for twenty minutes, not thirty

Twenty minutes fits in a lunch break at both ends. It is easier to say yes to, easier to schedule, and it sets a pace that keeps you off your own script.

You will get most of the value in the first twelve minutes anyway. The people who genuinely have the problem will run over on their own, and that overrun is your strongest signal of the whole exercise.

Where to actually find people

In rough order of how well they work when you have limited hours:

Your extended professional network, two hops out. Not your friends. Ask five colleagues or ex-colleagues for one introduction each to someone who has the problem. A warm introduction converts far better than anything cold, and it costs you one message.

LinkedIn, targeted narrowly. Search the exact role in the exact industry. Twenty well-chosen messages beat two hundred generic ones. Say who you are, that you are researching a specific problem, that you are not selling, and that you want twenty minutes. Your day job title is an asset here, so use it.

Communities where they already complain. Industry WhatsApp groups, subreddits, Slack and Discord communities, local meetups. Read for a fortnight before you post anything.

Anywhere you already have standing. If you work in the industry you are building for, you have more access than a full-time founder from outside it does. This is the genuine advantage of your situation and most people never use it.

Make scheduling cost you nothing

Scheduling overhead is what kills this. Three round trips of email to find a slot, times fifteen people, is hours you do not have.

Use a booking link with only your real availability on it: 7 to 8am, 1 to 1:45pm, and 8 to 10pm on weekdays, plus Saturday morning. Send the link in the first message. Let them pick.

Do not offer times you will resent. A slot you dread becomes a reschedule, and a reschedule usually becomes a cancellation.

Record everything, because you will not remember

You will do these across five weeks in tired evenings. Memory will not hold it.

Ask permission and record the call. If they decline, type notes during and spend five minutes immediately after filling gaps while it is fresh. Five minutes then saves twenty later.

Capture actual sentences, not summaries. "We export it to Excel every Friday and it takes two hours" is evidence. "They have reporting problems" is your interpretation, and by week four you will not be able to tell which was which.

What to ask when you only have twenty minutes

Ask about their past, not your idea. The past is fact. Opinions about your idea are noise, and polite people give encouraging noise.

Four questions carry most of the weight:

• Walk me through the last time you dealt with this. What did you actually do?
• What are you using today, including the spreadsheet and the WhatsApp group?
• What happens if it just does not get done?
• Have you ever paid for anything to solve this, or looked?

That last question does more work than the other three together. People who have searched for a solution have a problem. People who have paid for one have a budget.

Do not describe your idea until the final two minutes, if at all. The moment you do, they start being nice to you and the data stops.

Synthesise weekly, not at the end

Thirty minutes every Sunday, while it is still small. Three columns: what I heard repeatedly, what surprised me, what I now believe less than last week.

Doing this weekly beats one big session at the end, because it changes the questions you ask the following week. Fifteen interviews with a fixed script produce far less than fifteen where each week sharpens the next.

When to stop

Stop when three consecutive conversations produce nothing you have not already heard. That usually lands somewhere between twelve and twenty for a narrow enough segment.

If you are at twenty-five and still hearing new things every time, your segment is too broad. Narrow it and start again, because a problem that shows up differently for everyone is not yet a product.

The realistic timeline

Week one: build the list, send the first twenty messages. Weeks two to five: three conversations a week, synthesise each Sunday. Week six: decide. Either a pattern is there, or it is not.

Six weeks, roughly twenty-five hours, mostly in slots you were not using productively anyway. That is the entire cost of finding out whether the thing you have been thinking about for two years is real.

This is the Validate phase of LVL1 Startup School, run to a deadline with a mentor reading your interview notes and telling you when you are hearing what you want to hear.