Downdetector Outage: The Hidden Cost of No Upstream Dependencies

When the service designed to detect outages goes down, you learn something important about your dependencies. Downdetector’s November 2025 Cloudflare incident reveals the pragmatic reality of infrastructure decisions.

The Core Insight

Downdetector monitors website uptime—and during a November 2025 Cloudflare outage, Downdetector itself went dark. The irony was not lost on anyone. But the real story is more nuanced: Downdetector’s dependency on Cloudflare was a deliberate, defensible business choice.

The lesson: upstream dependencies aren’t always bad. Sometimes they’re the right trade-off.

Why This Matters

It’s easy to say “don’t depend on a single vendor.” It’s harder to actually evaluate whether that dependency makes sense. Downdetector’s situation illustrates the complexity:

• Multi-region, multi-cloud architecture
• But still depends on Cloudflare for DNS, CDN, and Bot Protection
• Why? Because the benefits (cost, speed, DDoS protection) outweigh the risks

For most products, this would be questionable. For Downdetector—the service that detects cloud outages—it’s pragmatic. They need to be able to detect failures across all major cloud providers, which requires being present on all of them.

Key Takeaways

The Business Reality:
– Downdetector is free to use, with limited monetization
– Without Cloudflare CDN, bandwidth costs would surge
– Site would be slower, revenue unchanged
– Net result: keeping Cloudflare makes business sense

What They Learned:
– Cloudflare control plane went down, but API stayed up
– More Infrastructure as Code could have helped recover faster
– The outage wasn’t global—they could shift traffic to reduce impact
– Bot Protection went haywire, blocking legitimate traffic

The Pragmatic Engineer’s Takeaway:

“Building redundancy at the DNS & CDN layers would require enormous overhead… With a team size in the double digits, building up a core piece of infra like this is a pretty tall order.”

Looking Ahead

The question isn’t “avoid all dependencies.” It’s “evaluate dependencies pragmatically based on your specific constraints.”

Downdetector made the right call for their situation. The incident prompted them to explore more improvements—but the core dependency remains. That’s honest engineering.

The next time someone tells you “never depend on X,” ask: “Based on what constraints?”

Based on analysis of Pragmatic Engineer “Downdetector and the real cost of no upstream dependencies”