BuiltWith

Brewer started BuiltWith in 2007 by inspecting page source on random startup sites — nobody had catalogued web technologies at scale yet. He built scrapers mapping code signatures to products (Adsense vs Adzerk, etc.) while working a corporate job in Sydney.

Interviews describe four years of evening work before revenue justified quitting. Co-founder Andrew Rogers joined with equity-only compensation and helped push Brewer full-time — but the product stayed deliberately lean.

BuiltWith fires up thousands of AWS EC2 instances running Brewer’s custom C# crawlers, stores technographics in MongoDB spread across servers, and keeps user accounts in Microsoft SQL Server — frontend ASP.NET on IIS, hosting through OVH (per interviews and the about page’s sustainability table listing OVH/AWS).

Startup Daily profiled Brewer as essentially running support, development, and ops himself — automated onboarding, email guides, no outbound sales team. Rogers stayed an advisor after leaving day-to-day work; the product did not bloat into a Salesforce org chart.

Industry write-ups (Colin Keeley, Startup Daily, BuiltWith about page) describe BuiltWith as one of the most capital-efficient businesses online — eight-figure ARR with Brewer as the sole full-time engineer/operator and minimal staff.

Metrics stay sparse by design: trials, customer signups, reports created. Brewer reportedly refused hiring until revenue cleared $100k/month and treats most dashboards as distractions. The stack never became the story — automated technographics at scale on boring Windows/Linux infra did.