The storyHow they got there
Tim Nolet and Hannes Lenke built Checkly from the Netherlands while Tim freelanced 50% of the time to keep the lights on. The product monitored APIs and browser transactions using Playwright — a developer-first alternative to Pingdom for teams who wanted code, not dashboards.
The first ten customers came from Tim's personal Twitter and blog driving technical readers to a free trial. The first hundred came from authoring "How to monitor [X]" tutorials that ranked on Google, plus open-source tools that all funneled back to Checkly.
At maturity, the channel mix: developer content including Tim's personal blog, dev.to posts, and conference talks (~40%), SEO on synthetic monitoring keywords (~25%), open-source contributions including Headless Recorder and Playwright integrations (~20%), and word-of-mouth among DevOps engineers (~15%). Outbound sales was killed early. Developer ergonomics and content were doubled down on.
Unit economics: CAC around $300–600, ACV around $2–5K, LTV around $8–15K, and net revenue retention above 120% from usage expansion as teams add more monitors. The company raised seed and Series A funding. Developer products are won by being the most credible voice on the problem — not by being the cheapest option.
Channel MixWhere the growth actually came from
Most case studies hand-wave channels. Here's the rough allocation — not in dollars spent, but in users acquired — across the routes that actually mattered.