How a Solo SaaS Founder Built a Product by Watching One Forum

**Fexingo** (0:01)
So, the founder we're talking about today did not write a line of code until he had spent six months reading the same online forum every single day.

**Luna** (0:10)
Six months of just reading? That is either extreme discipline or extreme procrastination. And I suspect you're about to tell me it paid off.

**Fexingo** (0:19)
It paid off to the tune of about $10,000 a month in recurring revenue within the first year.
His name is Dan, and he was a staff engineer at a mid-sized tech company in Atlanta working on backend infrastructure. Not a domain expert in accounting or tax prep, nothing like that. But he had a side project itch and wanted to build something for small businesses.

**Luna** (0:43)
So he picks a random forum? Or did he have a hypothesis about which community to watch?
So the classic listen before you build advice, but take into an extreme. Most people spend maybe a weekend reading Reddit threads and then start coding.

**Fexingo** (1:00)
Exactly. And Dan told me that the first month was mostly noise. Posts about which software has the best UI, complaints about IRS delays, general venting. But by the second month, he started noticing a pattern he called the Friday afternoon thread. Every couple of weeks, someone would post something like, I've got a client with a schedule C and a multi-state filing.
And I'm not sure if the deduction carries over correctly. Anyone dealt with this?
And the replies were usually a mix of guesses, links to IRS pubs. And one person saying, yeah, I ran into that last year. Here's a workaround I built in Excel.

**Luna** (1:39)
Okay. So the pain point is that the existing software doesn't handle edge case as well. And the preparers are essentially crowdsourcing compliance knowledge.
That sounds like a huge opportunity, but also potentially a very narrow one.

**Fexingo** (1:54)
Narrow is exactly why it worked. Dan didn't try to build a general purpose tax prep platform. He focused on one specific workflow, the multi-state schedule C deduction check. He found 15 threads over four months where preparers asked about that exact scenario. He even met a few of them not to pitch, just to ask clarifying questions.
By month five, he had a very clear spec for a tool that would check whether a specific deduction is valid in each state based on the filer's facts.

**Luna** (2:25)
So he validated the problem without a landing page, without ads, without even a prototype. How did he know they would pay?

**Fexingo** (2:34)
He posted a simple question in the forum.
If a tool existed that could check multi-state schedule C deductions in under two minutes, would you try it? He got 47 responses and 32 of them said yes, with several offering to beta test. He then asked the yes responders what they'd pay. The median was $40 a month. So he had a price anchor before he had any code at all.

**Luna** (2:59)
That's a really clean validation loop. One forum, one persona, one workflow.
I can see why it worked for a niche B2B product. But I wonder, does this method scale beyond very specific professional communities?
If you're building something for a broader audience, a single forum might not give you enough signal.

**Fexingo** (3:20)
That's a fair challenge. I think the principle scales, but the execution changes. For a broader consumer product, you might need to monitor multiple forums or use something like Reddit's API to search across subreddits for a recurring pattern of complaint. But the core insight is the same.
Find a place where your target users gather voluntarily to discuss their problems and just watch. Don't project. Don't survey.
Watch what they actually say when they're not being asked.

**Luna** (3:51)
Let me play devil's advocate again. What if the forum is full of power users who are not representative of the broader market? Tax preparers who hang out on Reddit might be more tech savvy and more willing to try new tools than the average preparer.

**Fexingo** (4:05)
That's a real risk. Dan acknowledged it.
But he also found that the forum's users were often the ones their colleagues came to for advice. They were micro influencers within their own firms and networks. So if you can win them, you get word of mouth into the less tech forward segment. And in practice, that's exactly what happened after launch. About 40 percent of his early customers came from referrals by forum members who were not the original beta testers.

**Luna** (4:33)
Okay.
So the forum served as a beachhead.
I buy that. Let's talk about the build itself.
How long did it take him to go from spec to a paid product?