Simple Products: What HostingChecker and Expired Domains Teach

When most people hear the word “product,” they picture an app with dozens of screens and an endless roadmap. At DIGITAL WOLF we prefer the opposite extreme: a tool that does one thing and does it properly. We built two of them — HostingChecker.org, which tells you who hosts any given website, and Expirovanedomeny.cz, a search engine for available and expiring .cz domains. Neither is a big product. Yet they taught us more about building software than many large client engagements. Here are five things we take away from them — and why we bring the same thinking to client work.

One thing, done properly

The oldest good advice in software still holds. The Unix philosophy sums it up in Doug McIlroy’s line: “Write programs that do one thing and do it well.” (Unix philosophy, Wikipedia) This isn’t nostalgia for the command line — it’s a design principle. A narrow scope means a clear brief, fewer states the product can end up in, and an interface that needs no manual.

HostingChecker answers a single question: who is behind this website? It detects the hosting, DNS and tech stack. It doesn’t do monitoring, doesn’t generate reports, doesn’t send emails. Expirovanedomeny.cz also solves one thing: which .cz domain is being released right now and is worth a look. That narrowness lets you design the product so a user grasps the value in five seconds — no onboarding, no sign-up. That is nearly impossible with large apps.

Takeaway: before you start building, write in one sentence the question your product answers. If you need the word “and” in there, you probably have two products.

Data is the moat, not the feature

Anyone can copy a feature over a weekend. Data, they can’t. That is why more than half of investors now name proprietary data as the most durable advantage a startup can hold — often more durable than the algorithm itself (Elad Gil: Defensibility & Competition).

In both of our tools the value lives in the data, not the UI. HostingChecker is only as good as the accuracy of its hosting and technology fingerprints — and those take years to build and clean. Expirovanedomeny.cz combines a daily view of released domains, CZ.NIC auctions, Web Archive history and SEO signals into a single view; that combination is work, not a feature.

An important caveat: static datasets age and eventually get replicated. The real moat comes from data that refreshes itself — from daily operation, from usage, from fresh records. That is why we build both tools as daily-updated feeds, not one-off exports.

Takeaway: ask what in your product can’t be downloaded or copied. If the answer is “nothing,” you’re building on sand.

SEO as distribution, not an afterthought

A small product has no advertising budget. But it has something else: every answer it can give is also a page someone is searching for. And organic search still drives roughly 53% of all website traffic — more than every paid channel combined (Search Engine Land / BrightEdge).

The textbook example is Zapier. For every combination of apps it generated a dedicated page — over 50,000 landing pages that together pull millions of visits a month (Practical Programmatic: Zapier). The key isn’t the number of pages, it’s that each one answers exactly what a person types into search.

A tool with its own data gets this model for free. Every query about who hosts a given domain is a potential page. Every expiring domain is a record someone googles. Distribution isn’t a separate marketing activity — it’s baked into how the product is built.

Takeaway: design the product so its outputs are indexable pages, not just screens behind a login.

The tool as agency marketing

A free tool is one of the best forms of content, because it delivers value before it asks for anything. HubSpot built an entire ecosystem on this — its Website Grader and other tools are free and act as the front door to the product (HubSpot free tools). Ahrefs reports that its free Webmaster Tools brings in thousands of users a week, a share of whom convert to paid plans (Ahrefs: Lead Generation).

For an agency this approach has one more layer. A working tool is proof, not a promise. When someone sees that we can build HostingChecker (Symfony 8 backend, Next.js frontend) or a daily-updated domain search engine, we don’t have to argue that we can build software — it’s visible. That builds trust better than a case study, because the customer can try it themselves.

Takeaway: instead of another whitepaper, consider a small tool that solves a real problem for your audience. It’s content that gets used again and again.

Operations that don’t consume the team

A small product only makes sense if it runs itself almost entirely. A narrow scope makes that possible: fewer features mean fewer things that can break. Expirovanedomeny.cz runs on daily batches — fetch, evaluate, publish — with nobody sitting over it. HostingChecker answers queries and maintains its fingerprints without manual work. Here automation isn’t a bonus, it’s the condition for the product to be worth running at all.

It’s the same thinking we bring to custom apps: design operations so the cost of one more user is close to zero.

Summary

A simple product isn’t an unfinished product. It’s a deliberate choice: one narrow problem, proprietary data as a moat, SEO as built-in distribution, the tool as proof of capability, and operations that almost run themselves. HostingChecker and Expirovanedomeny.cz aren’t a business in their own right for us — they’re the lab where we test these principles, and the proof that they work.

This is exactly how we think when we build custom software at DIGITAL WOLF — whether it’s a small internal tool or an app you build on your own data. If you have a narrow problem worth solving properly, get in touch — we’ll happily think it through with you, from data to distribution.