Four dev-tool ideas this week. Four dead, all from the same cause, and it took me embarrassingly long to see the pattern instead of just the individual rejections.
I'm a solo dev, no team, no funding, building in public-ish. The move I keep reaching for is the classic one: ship something free (a CLI, a GitHub Action, a linter) that devs adopt for free, then sell a paid backend on top: history, dashboards, team alerts, whatever the free tool can't do alone. It's the Sentry/Vercel playbook, scaled down. It's also, as of 2026, mostly a trap if you're doing it alone with no existing audience. Here's the check I wish I'd been running from idea one instead of idea four.
The idea that looked good on paper
The one I actually got excited about: flaky-test analytics. Real, universal pain (every CI setup eventually has a test that fails 1 time in 20 for no reason), and unlike most of my other ideas, there's an actual company charging real money for it. BuildPulse has been selling this since around 2019, three tiers, $99/$249/$499 a month, same structure on the pricing page for years. That's rare. Most "obvious" dev-tool ideas don't have anyone visibly paying for them at all.
So I went looking for the wedge: free CLI/Action reads your JUnit XML, no write access needed, dead simple to adopt. Then I checked who else is standing in that spot.
Trunk.io raised $28.5M in venture funding. Their flaky-test detection is free for any team under 5 monthly active committers, and it already works with GitHub Actions today. That's not a roadmap promise, that's the current pricing page. Datadog bundles flaky-test tracking into CI Visibility at $8/committer/month, money most teams are already spending on Datadog for other reasons. Cypress Cloud includes flake detection starting at $67/mo. Gradle has a named "Flaky Test Detection" feature in Develocity. None of these companies built flaky-test detection as the product. They built it as a reason to keep you inside a bigger bill you already pay.
The wedge I wanted, free CLI for small teams not big enough for Datadog, is exactly the slice Trunk.io just made free. Not "hard to compete with." Actually free, today, for my target customer.
Same shape, different idea
I ran the same check on a completely different idea (cross-repo drift detection, catching when a bugfix in one repo doesn't get propagated to its sibling repos, something I'd noticed doing OSS work across a bunch of related codebases). Different problem, same two walls.
Low end: Renovate (21,901 stars, free, AGPL) and GitHub's own Dependabot already handle dependency-drift-across-repos for zero dollars. Multi-gitter (1,212 stars, free, Apache-2.0) already does bulk cross-repo PRs. High end: Moderne, the closest real competitor, closed a $30M Series B in early 2025, roughly $50M raised total, and their OpenRewrite tech is already embedded in bigger vendors' code-automation stacks. Sourcegraph raised $245M and sits at a $2.6B valuation. Snyk, if you frame it as a security-drift problem instead, has raised $1.6B.
Free OSS eating the bottom, $50M-to-$1.6B-funded companies owning the top via enterprise trust (SSO, compliance, the stuff that makes a security team say yes) that I cannot produce alone. No gap in the middle. Same shape as flaky tests. Same shape, it turns out, as a CI-autofix idea I killed a week earlier too: GitHub's own Copilot Autofix already owns that lane by default, built into the platform, and the two independent players in that space (Sweep, Korbit) didn't survive as independents either. One pivoted its whole product to a JetBrains plugin, the other got folded into a security company two months ago.
I started calling this the sandwich. You're the filling.
The actual check (steal this)
Before I sink a week into a "free tool, paid backend" idea now, I ask two questions, in this order:
- Is a funded company already giving away the exact free-tier version of my wedge, on purpose, as customer acquisition for something bigger? Not "could they." Is there a live pricing page right now where my target customer gets it free. This isn't rare in 2026, it's the default move for anyone with a seed round.
- Does actually landing a paying customer require trust infrastructure I can't produce solo (SSO, compliance paperwork, security audits, an incident-response story)? If the buyer needs to trust the company as much as the tool, that buyer is not going to hand a credit card to an anonymous solo dev with a GitHub repo, no matter how good the tool is.
If the answer to both is yes, I stop. Not "make the free tier better," not "find a niche within the niche." Stop, because the structure doesn't change with more effort. It changes with more funding or an existing reputation, neither of which building harder gets you.
The part that took me longest to internalize: real pain is not the same thing as willingness to pay. Flaky tests are a genuinely universal complaint. Nobody's going to argue with you that it's annoying. But the fix for that pain is already a checkbox inside four different tools teams already have open bills with — so the pain being real doesn't mean anyone owes a fifth, separate invoice to a stranger. A tool that only flags a problem (a linter, a checker, a "here's what's wrong" CLI) is the weakest version of this trap, because a check is a feature, and features get copied into the next platform release for free. They don't get billed separately. If your whole product is "I noticed the bug," you don't have a product, you have a feature request someone bigger will ship next quarter.
What actually did survive the check
Not everything did die, which is the part worth keeping. Two patterns from this same search held up under the same scrutiny, and neither of them is "free tool, hope people upgrade."
IPinfo (IP geolocation data, one guy, Ben Dowling, out of a Stack Overflow post in 2014) never had a free-adoption funnel at all. It's metered API access, paid from day one, grew off SEO and dev search instead of a personal audience. Sidekiq (Mike Perham, background-job processing for Ruby, solo for most of its life, reportedly into seven figures a year) kept the free OSS core but sold the paid layer as a license key for extra features shipped in code, not a hosted SaaS with dashboards and team seats. No infra to run, no "please upgrade" funnel to babysit, no enterprise trust apparatus required because you're not asking anyone to hand you their CI pipeline's write access.
The thing both have in common: neither one is trying to convert someone else's free users. They charge their own users, directly, for a scoped thing, from the start. That's the opposite move from "give it away and hope."
Back to idea five. At least now I've got a filter that kills the bad ones in an afternoon instead of a week.
Written by **greymoth. I build developer tools and write about where software quietly breaks — Japanese/CJK edge cases, i18n, the boring infra nobody checks. → *glovrex.com** · github.com/greymoth-jp*
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