There's a difference between a market that looks interesting and one that's actually ready to spend money. Most founders waste months chasing the former. The signals below aren't about vibes or trend reports — they're about observable, repeatable behaviour that points to real, monetisable demand. Track these, and you'll spend less time building for nobody.
1. Unanswered questions on Stack Overflow
Stack Overflow's unanswered questions are a goldmine. When a question sits unanswered for months, it usually means either nobody knows the answer — or the tooling to solve the problem doesn't exist yet. Both are signals worth noting.
Filter by tag and look for clusters. If dozens of people are asking variations of the same thing with no good answer, that's a gap.
2. Recurring "How do you handle X?" threads on Hacker News
Search HN Algolia for "how do you" plus your niche. When the same question resurfaces every 12–18 months with hundreds of comments, the problem hasn't been solved well. The comments themselves are often more valuable than any survey you could run — people are brutally honest about what's broken.
3. GitHub Issues with high comment counts but no resolution
Open a popular repo in your niche and sort issues by comment count. A thread with 80+ comments and an "open" label after two years isn't a bug — it's a product opportunity. GitHub Issues reveal exactly what paying users of existing tools wish existed.
4. Workaround threads (the "I just use a spreadsheet" signal)
When people describe elaborate manual workarounds — spreadsheets, Zapier chains, copy-paste rituals — they're telling you the current tools fail them. Search for "I just use" or "we manually" in forums, Reddit, and Ask HN threads. Every workaround is a product waiting to exist.
5. Products launching repeatedly in the same category on Product Hunt
If you see three or four tools solving similar problems launch on Product Hunt within 12 months, something's happening. It means founders independently believe there's a market — and at least some of them are getting upvotes, which means users agree. This isn't crowded; it's validated.
6. GitHub Trending repos with no obvious monetisation
When a tool hits GitHub Trending and has thousands of stars but zero business model, that's often a signal. People want the capability but no one's turned it into a product yet. If you can wrap a clean UX and pricing around it, you're not building from scratch — you're building on demonstrated demand.
7. Job boards listing niche-specific roles at scale
If you suddenly see 40 job postings for "email deliverability specialist" or "customer data analyst" across companies of all sizes, a function is becoming mainstream. That mainstream adoption usually creates room for tooling. People hire before they buy software — so job boards often predict SaaS demand by 12–24 months.
8. Consultants charging premium rates for something that could be automated
Find the Upwork and Toptal listings. When consultants are charging $150/hour to do something repetitive — scraping, reporting, migrating data — it means the work is valuable but the tooling is absent. That rate is your willingness-to-pay signal. If companies spend $5k/month on a human to do it, they'll pay $500/month for software.
9. "Is there a tool that..." posts with upvotes
Search Reddit, Hacker News, and niche Slack communities for "is there a tool that" or "does anything exist for." These posts are direct demand signals with zero ambiguity. When a post asking for a specific tool gets 200 upvotes and 60 replies, someone should be building it. Maybe that someone is you.
10. Ask HN: Who's Hiring threads with recurring tool mentions
Scroll through Ask HN: Who's Hiring threads from the past two years. When job descriptions start requiring proficiency in a specific tool that didn't exist three years ago, that tool found product-market fit. The inverse is also useful: if job descriptions list 6 different tools to do one job, there's probably a consolidation play waiting.
11. Negative reviews of category leaders that repeat the same complaint
Don't just read G2 or Capterra reviews to feel good about a competitor's weaknesses. Look for structural complaints — things people say every tool in a category gets wrong. If every review of every email marketing platform mentions "deliverability reporting is terrible," that's not a competitor weakness. That's a category gap.
12. Discord and Slack communities growing faster than their subreddits
Community growth rate is a demand proxy. When a niche Discord hits 10,000 members faster than the equivalent subreddit did, it signals that practitioners in that space are actively seeking peers — which means the field is moving fast enough that people need real-time help. Fast-moving fields need fast-moving tooling.
13. The "I wish Notion/Airtable/Excel could just..." complaint pattern
When people hack together solutions in horizontal tools, they're revealing a vertical need. Search Twitter, Reddit, and Ask HN for "I wish [generic tool] could." The complaints are product specs. The frequency of the complaint is your TAM estimate.
14. Stack Overflow tags growing faster than the parent technology
If a framework has 10,000 tagged questions but a specific use-case tag is growing at 3x the rate of the parent, that use case is becoming dominant. It means the community's real interest is ahead of where the tooling sits — classic early-mover territory for a focused SaaS product.
15. Hacker News Show HN posts that get traction but then disappear
Use HN Search to find "Show HN" posts in your niche from 2–4 years ago that got strong upvotes and comments but whose products no longer exist. This tells you two things: the idea had real interest, and execution (not demand) was the bottleneck. With better tools, better distribution, and more experience, you might be able to succeed where someone else couldn't quite close the loop.
The noise you can safely ignore
Not every signal is worth tracking. Ignore:
- Social media follower counts on influencer accounts in a niche
- "Interest" forms with no pricing attached
- App store download counts without revenue context
- Trending hashtags that spike and collapse in under a week
These feel like data. They're not. They measure attention, not intent.
How to track all of this without losing your mind
Manually monitoring 15 signals across Stack Overflow, GitHub, Hacker News, and Product Hunt is a full-time job. In practice, most indie hackers check one or two of these occasionally and miss the pattern entirely — because the signal only becomes clear when you aggregate across sources over time.
That's exactly what Niche Sonar is built for. It pulls together demand signals from across the sources that actually matter — forums, repositories, job boards, community discussions — and surfaces the patterns before they become obvious to everyone else.
If you're in the early stages of validating an idea, or you're looking for your next niche before committing months of development time, try it free. No credit card required.